SYNOPSIS OF THE ORDERS OF CHILOPODA.

1. ANAMORPHA.

Nineteen segments with fifteen pairs of legs.

Seven or fewer segments with stigmata. Tracheae not anastomosing.

Some of the tergites are much reduced or have disappeared completely, so that the number of tergites is not more than eight.

The sternite and the coxae of the maxillipedes separated or a coxosternum with median suture.

The female has gonopods with spurs on the praegenital segment. Intercalar tergites present only in Craterostigmus; praesternites never present.

The young leave the egg with seven pairs of legs. Development with hemianamorphosis.

A. Scutigeromorpha.

Tracheae opening by seven unpaired stomata on the middle of the dorsum near the posterior border of the tergites.

Tracheae not branched.

Eyes faceted.

The clypeus lying on the dorsal side; the mouth near the anterior end of the head.

Antennae composed of a short, indistinctly 2-jointed shaft and a long multiarticulate flagellum, divided by special joints into two or three portions.

First maxillae with a peculiar sense-organ.

Eight tergites.

B. Lithobiomorpha.

Tracheae opening by stigmata in the pleurae between the tergites and coxae.

Tracheae ramified.

Ocelli single, or in groups (no compound faceted eyes), or wanting.

The clypeus lying on the ventral side; the mouth remote from the anterior end of the head.

Antennae not divided into sections by special joints.

First maxillae without a peculiar sense-organ.

Fifteen tergites of different sizes, sometimes (Craterostigmus) six intercalar tergites.

2. EPIMORPHA.

Twenty-five or more segments with 21, 23, or 21-170 or more pairs of legs.

Nine or more pairs of stigmata. Tracheae anastomosing.

All main tergites of nearly the same size. The tergites often divided into main tergites and praetergites.

Praesternites always present.

Coxosternum of the maxillipedes without median suture.

The female has only small and unspurred gonopods on the praegenital segment, or none.

The young leave the egg with the full number of legs. Development with anamorphosis.

A. Scolopendromorpha.

Body robust, legs long, movements quick.

Antennae with 17-20 or more joints.

Four ocelli on each side, or none.

21 or 23 pedal segments.

9, 10, 11, or 19 pairs of stigmata.

Last legs strongly curved with a robust claw, except in Alipes, where they are racket-shaped and clawless.

B. Geophilomorpha.

Body very long and slender, worm-like, legs and antennae short, movements slow.

Antennae 14-jointed.

No eyes.

31-170 or more pedal segments.

All pedal segments except the first and the last with stigmata.
Last legs straight, and generally weak and resembling antennae.
Labrum and mandibles very different from the rest of the Chilopoda.

1. Subclass Chilopoda Anamorpha Haase.

1880. Haase, Schles. Chilop., i, p. 6.

1885. Meinert, Myr. Mus. Cantabr., Trans. Amer. Phil. Soc., p. 163.

1887. Haase, Indo-Austral. Chilop., p. 14.

1893. Bollman, Bull. U.S.A. Mus., No. 46, p. 164.

1895. Silvestri, Ann. Mus. Civ. Genova, 21, xlv, p. 622.

1908. Hennings, Zool. Ann., ii, p. 68.

1914. Attems, Indo-Austral. Myr., p. 87.

1. ORDER SCUTIGEROMORPHA Poc.

1895. Pocock, Biol. Centr. Amer., p. 1.

1902. Pocock, Quart. J. Micr. Sci., xliv, p. 447.

1907. Verhoeff, Bronn's Class. u. Ordn., p. 224.

The Scutigeromorpha are in some respects aberrant from all other Chilopoda, and the group has been defined in the same manner by all the writers from Leach, Gervais, to Haase, Latzel, Meinert, and the recent authors. Pocock and Verhoeff placed this group, as Notostigmophora, in opposition to the other three orders. The system of genera and species was put forward by Verhoeff, and we cannot do better than accept his systematic arrangement of the genera, the more so as nearly all the genera, excepting Scutigera and Scutigerina, were erected by him. Furthermore, the number of South African species is too restricted to justify a revision of the arrangement of the whole order. I can touch only upon single points.

Two species are represented in the collection of the Museum; the first is a subspecies of the well-known Palaearctic Scutigera coleoptrata; the second, Scutigerina weberi, was so badly described by its author that Verhoeff could not include it in his system. It belongs undoubtedly to the subfamily Scutigerinae, and represents a new tribe of this subfamily. If we accept the existing subfamilies, the characters distinguishing this genus from all other Scutigerinae are decidedly more important than the characters separating the tribes Scutigerini, Ballonemini, and Thereuonemini. These characters are, firstly, the male gonopods: low, blunt, pubescent cones, so rudimentary on the praegenital segment that they are nearly invisible, while they are slender styles in all hitherto known Scutigerinae. It seems to be similar in this respect to the Pselliophorinae, which I do not know. The position of the gonopods in Scutigerina and Pselliophorinae is different, however; in Scutigerina they are far apart on the sides of the segment, in the Pselliophorinae they are close together.

The second character is the absence of the longitudinal keeled edges of praefemur, femur, and tibia, which are present in all other Scutigeromorpha.

We divide, therefore, the Scutigerinae into two groups: Scutigerininae (with Scutigerina), and Scutigerae with three tribes, Scutigerini, Ballonemini, and Thereuonemini, with the admission that the limits of these three tribes are somewhat vague and that we do better not to adopt them. In his last paper on this subject

(Bronn's Class. u. Ordn.) Verhoeff distinguishes the tribes in the first case by the number of the joints of the first flagellum of the antennae, a character morphologically so insignificant that we can put a species with less than 90 joints with the Ballonemini, if all the remaining characters call for this position (Ribaut did it in the case of Ballonema jeanneli), or a species with more than 100 joints with the Scutigerini or the Thereuonemini. The second character used by Verhoeff is that of the spines on the tergites. Verhoeff says: Ballonemini, tergites beset with spine-bristles (Stachelborsten), without spines (Dornen); Scutigerini and Thereuonemini, with spines dispersed over the surface and serrate on the margins. These terms lead us to believe that the second group (Scutigerini and Thereuonemini) has no spine-bristles, but this is not correct. The position is that the Ballonemini have no spines, the other tribes have spines. Both groups have spine-bristles. I assume it to be agreed upon that the prominences of the chitin-skeleton must be divided into two groups: (1) simple rigid prominences-hairs, spiculae, and spines; and (2) non-rigid prominences into which a nerve-ending enters-setae and spine-setae (spine-bristles).* The spines are strongly thickened hairs. The Ballonemini possess spiculae besides the spine-bristles, therefore the difference between the Ballonemini and the other tribes is purely one of degree as regards the presence or absence of spines, the spiculae being nothing else than little spines.

The remaining characters used by Verhoeff, viz. tarsal papillae (Tarsalzapfen), tarsal spines (Tarsalstachel), are not general, and each distinguishes the Ballonemini only from a part of the other tribes.

Good characters for a further differentiation are the spines on the telopodites of the second maxillae and the hairs on the ventral side in Scutigerina, characters which are as good as unknown in the remaining genera.

We arrive at the following system :

Fam. SCUTIGERIDAE Verh.

1. Subfam. SCUTIGERAE nov.

The male gonopods of both segments (praegenital and genital) are slender styles. Praefemur, femur, and tibia of the legs with sharp, longitudinal, spiny edges. The tergites with spines or spiculae.

Cf. Verhoeff, Uber Gattungen der Spinnenasseln. Ges. Naturforsch. Freunde, Berlin, 1904, p. 247.

1. Tribe Scutigeri.

The joints of the antennae much broader than long. Both pairs of male gonopods are slender, distant styles.

Key to the Genera of Scutigeri.

la. Legs 6-14 with two spines on the first tarsus

2a. Tergites without spines. Legs 1-14 with tarsal papillae

2.

Ballonema Verh.

26. Tergites with spines. Legs 1-9 with tarsal papillae, legs 10-14 without papillae

3. 3a. On the tarsus of the anterior legs joints with large papillae of equal size alternate with joints without papillae Scutigera Lam. 36. On the tarsus of the anterior legs joints with large papillae and joints with small papillae alternate. Lassophora Verh., Diplacrophor Chamb.

1b. All legs without tarsal spines

4a. Tergites with numerous long needle-like hairs 46. Hairs short, conical, or wanting

4. Thereuonema Verh. 5.

5a. Tergites without hairs but with numerous spines and short spine-bristles

Tachythereua Verh.

6.

5b. Tergites with hairs between the stouter spines and bristles 6a. The sides of the basal joints of the syntelopodite of the female gonopod are parallel; the sinus between the terminal branches is narrow, elliptical 7. 7a. The surface of the last 2 tergites and the lateral border of the last 3 tergites beset with spines; the spine-bristles, if present, not longer than the spines Allothereua Verh.

76. The last tergites with numerous spine-bristles; the spines, if present, at most half as long as the spine-bristles Parascutigera Verh.

66. The basal joints of the female gonopods are much enlarged distally; the sinus between the terminal branches a very broad semicircle 8. 8a. The terminal branches of the female gonopod distinctly separated from the basal coalesced part Prionopodella Verh.

86. The terminal branch of the female gonopod not separated from the basal coalesced part 9.

10.

9a. The border of tergites 6 and 7 with strong spines forming a saw 10a. The area surrounding the stomata of tergites 6 and 7 with 12+12 or more strong spines. Stomata 6 and 7 oblong .

106. The area surrounding the stomata without spines.

Thereuopoda Verh. Stomata 6 and 7 very Prothereua Verh.

short 96. Spine-bristles preponderating on the border of tergites 6 and 7; between them short spines not forming a saw

Thereuopodina Verh., Podothereua Verh.

2. Tribe Pselliophori.

The joints of the antennae are as broad as long or longer than broad. The gonopods of the male praegenital segment are broad, lamelliform, and touch one another (Pselliophora Verh., Sphendononema Verh.).