326 



GEOLOGICAL SUEVEY OF THE TEEEITORIES. 



We sliould regard A. longicaudatus as standing at the head of the 

 genus, and the European species, A. cancriformis, lowest, the former 

 species being on the whole more specialized," since the carapace is in A. 

 longicaudatus smaller, not reaching to the middle of the whole body, 

 while that of A. cancriformis is more as in the larval stages, since it 

 reaches nearly to the telson, nearly concealing from above the limbs. 

 The frontal doublure is also much smaller than in the European species, 

 while in the latter species the caudal appendages are considerably longer 

 than the body, in A. longicaudatus being barely one-half as long as the 

 whole body. On the whole, therefore, A. longicaudatus seems nearer 

 allied to BrancMpodidcc, while A. cancriformis, by its large shield cover- 

 ing nearly the whole body, shows some slight approximation to the Limna- 

 diadce. 



Apus doming-ensis Baird. 



"J.JJMS Domingenais Baird, Proc. Zool. Soc. London, Part xx, 5 (Tab. 22, fig. 1), 1852. 



"Clypeo corporis dimidiam partem tegente, 

 rotundo, tenui, corneo; ramo externo pedum 

 primi paris corpus aequante. Long, toti corporis 

 1 poll; lat. clypei f poll. 



"-Haft. — In Insula St. Domingo, India Occi- 

 dental!. CoUegit M. Salle. Museum Britanni- 

 cum. 



" Though a native of the West Indies, this 

 species may be easily distinguished from A. 

 Guildingii by its round-shaped carapace of a 

 horny colour, covering half the body of the ani- 

 mal, and its external branch of the first pair of 

 feet only the length of the body, whih^, in A. 

 Guildi7igii it exceeds the whole body and caudal 

 filament included. The carina down the center 

 of the carapace, and the fork which it takes at 

 the anterior extremity where the division into 

 cephalic and thoracic portions takes place, are 

 marked throughout their length with a deep 

 brown color, as are also the short stout spines 

 on the abdominal portion of the body. These 

 are straight, not hooked, as in some of the other 

 species. The caudal filaments are nearly the 

 length of the body, and are covered with very 

 numerous, extremely short set«. The ovipar- 

 ous feet are present in all the specimens I have 

 examined, but none contain any ova." 



This species (Fig. 16) is very closely allied to 

 A. cequalis, and represents that species in the 

 West Indian fauna. 



riG. 16. — Apus domingensls, en- 

 larged. After Baird. 



Apus guildingii Thompson. 



Apus Gtdldingii Thompson, Zool. Eesearclies, Fasc, t. 108, t. 6, fig. 3; Milne-Ed- 

 wards, Hist. Nat. Crust, iii, 561. Baird, Mouog. Family Apodida;, Proc. Zool. Soc. 

 London, Pt. XX, 3, 1852. Clypeo corporis vix dimidiam partem tegente, quadrato, 

 membranaceo, nigrescente ; ramo externo pedum primi paris longissimo, totum cor- 

 pus, lilanientis caudalibus inclusis, excedente. 



Hal). — In Insula " St. Vincents," India Occidentali ; Eev. Lansdowne 

 Guilding. 



