English: EXPLANATION OF PLATE 23,

Illustrating Mr. Pocock's paper, " A New aud Annectant Type of Chilopod."

(Tlie figures, depicting the structural features of Craterostigmus tasmanianus, were drawn by Mr. Pocock from the specimens of this centipede which are preserved in the Natural History Museum.)

i'lG. 1. — Dorsal view of anterior extremity, c. Ceplialite or head shield. 0. Eye. sf. Frontal suture, a. Antenna, bp. " Basal plate " = tergum of toxicognatli. pi. Pleural sclerite of toxicoguath. ex. p. Coxal plate. /. Femur or third segment, p. Patella or fourth segment, t. Tibia or fifth segment, cl. claw or sixtli segment of toxicognath. 1, 2, 3. Terga of first, second, and third somites.

Fig. 2. — Ventral view of toxicognaths, showing the praecoxal processes of the coxal plate {ex. p.), the second segment or trochanter (^a), which is fused with the third segment or femur (/. ), the prseaxial teeth of the latter, and the completeness of the fourth and fifth segments {p., t.) on the post-axial side of the appendage.

Ftg. 3. — Lateral view of head and anterior extremity of body. Lettering of head and toxicognath as in Fig. 1. 1 — 7. Terga of anterior seven somites, numbers 3 and G being without sternal representatives. 1' — 5'. Sterna of anterior five leg-bearing somites. s. Stigmatic, and ms., metastigmatic sclerite. pi. m. Membrane of pleural area. ex. Coxa or basal segment of leg. pcx. praecoxal sclerite. /«. prsesternal sclerite.

Fig. 4, — Lateral view of posterior extremity of body. 15 — 21. Terga of fifteenth to twenty-first somites. 10' — 15'. Sterna of tenth to fifteenth leg-bearing somites. The rest of the lettering as in Fig. 3.

Fig. 5. — Dorsal view of last leg-bearing somite with ano-genilal capsule {uff.) projecting from its posterior extremity. L Tergal area of somite. 1 aud 3. First aud base of third segment of leg of fifteenth pair.

YiG. G. — Ventral view of last leg- bearing somite and of ano-genital capsule (ctff.). 1 — 3. rirst, second, and base of third segment of leg of four-teenth pair. 1', 3'. First and base of third segment of leg of fifteenth pair. s. Sternal area of last leg-bearing somite, ps. Fused prsesternal element.

Yie. 7. — Lateral view of the ano-genital capsule (ar/.) and of the posterior half of the last leg-bearing somite. la(. Lateral area of this somite. 1. Basal segment of the leg.

YiG. 8. — Ventral view of cephalite or head plate, a. Basal segment of antenna, sf. subfrontal or retroverted praiantennal area with labral sclerites.

Fig. 9. — Labrum. L Teeth, m. Membranous lateral portion of excision.

FiGr. 10. — Lower or posterior aspect of mandible or gnathite of first pair. /. Fringe of hairs at its distal extremity.

F'iG. IL — Upper or anterior aspect of the same. /. Fringe of hairs. i. Pectiniform teeth. /. Membranous lobe.

I'lG. 12. — Distal extremity of the last still more enlarged, showing the series of nine pectiniform teeth arranged in groups of threes.

I'lG. 13.— Inferior or posterior view of gnathites of the second pair (maxillae). 1. Basal segment bearing the biscgmented ectocorm (1, 2) and the one-jointed ectocorm (i/iL).

Fig. 14. — Lower or posterior view of left palpognath. 1. Ectocoxite. 1'. Entocoxite. 2 — 5. Secoiid to fifth segments, the second, or trochanter, fused with the third, or femur.

F'lG. 14 a. — Distal segment of the same from its anterior or upper side, showing fringe of hair.

Fig. 15. — Lateral view of part of the third leg-bearing somite (fourth somite from the dorsal side). L Tergum. s. Stigmatic sclerite with stigma. tiis. metastigmatic sclerite. pL Pleural membrane.

i'lG. 16. — Leg of fourteentii i)air. 1 — G. Segments; 2 with inferior spike, 5 and 6 with spines.

l"iG. 17. — Basal portion of same. laL Part of lateral portion of the four-teenth leg-bearing somite. 1. Basal segment or coxa of leg withsubspherical excrescence or nodule («.). 2. Second segment or trochanter with spike {sp.). 3. Base of third segment or femur.

Fig. 18. — Leg of the fifteenth pair. 1 — 7. First to seventh segments, the sixth and seventh representing the sixth of Fig. 16 ; 1 with inferior spike, 2 ankylosed to 3.

Fig. 19. — Basal portion of same. laL Lateral area of part of fifteenth leg-bearing somite. 1. Basal segment or coxa with («.) nodular prominence and {sp.) spike. 2. Remnant of the second segment or trochanter fused with the base of the third segment or femur (3).