70 BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



Genus HOMOLOGENUS A. Milne Edwards 



Homolopsis A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, p. 34, 1880, 

 (type, H. rostratiis A. Milne Edwards). Not Homolopsis Bell, Monograph 

 of the fossil malacostracous Crustacea of Great Britain, pt. 2, p. 22, 1862 

 (1863). 



Homologenus A. Milne Edwards, in Henderson, Voyage of H. M. S. Challenger, 

 Anomura, vol. 27, p. 20, 1888. — Boitvier, Bull. Soc. Philom. Paris, ser. 8, 

 vol. 8, p. 30, 1896. — A. Milne Edwards and Bouvier, Crustaces decapodes 

 provenant des campagnes du yacht VHirondelle (supplement) et de la 

 Princesse-Alice, fasc. 13, p. 13, 1899; Mem. Mus. Comp. Zool., vol. 27, 

 p. 29. 1902. 



Differs from Thelxiope in its much longer rostrum, almost styli- 

 form, and armed near the middle of its length wdth a pair of sym- 

 metrical spines, by the reduction of the anterolateral spine, the great 

 development of the marginal spine which limits outwardly the anten- 

 nal region, the presence of a strong metagastric spine; and by the 

 regular convexity of the carapace which is dilated behind and pre- 

 sents no trace of dorsolateral margins; epistome narrow, scarcely 

 soldered with the front. 



Eastern Atlantic (off Morocco and Azores); western Atlantic 

 (Bahamas and West Indies); 580 to 1,039 fathoms. 



HOMOLOGENUS ROSTRATUS (A. Milne Edwards) 



Figure 17; Plate 17, Figures 1-3 



Homolopsis rostratus A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, p. 34, 

 1880 (type locality, between St. Thomas and Santa Cruz, 580 fathoms; 

 whereabouts of type unknown) ; Recueil de figures de Crustaces nouveaux 

 ou peu connus, pi. 6, fig. 1, la, 1883. 



Homologenus roslratus Bouvier, Bull. Soc. Philom. Paris, ser. 8, vol. 8, p. 30, 

 fig. 25, 1896. — A. Milne Edwards and Bouvier, Expeditions scientifiques 

 du Travailleur et du Talisman, pt. 1, Crustaces decapodes, 1880-1883, 

 p. 11, pi. 1, fig. 1 (col.), pi. 8, figs. 19-21, 1900; Mem. Mus. Comp. Zool., 

 vol. 27, p. 30, 1902. 



Homologenus (Homolopsis) rostratus A. Milne Edwards and Bouvier, Crustaces 

 decapodes provenant des campagnes du yacht VHirondelle (supplement) 

 et de la Princesse-Alice, fasc. 13, p. 13, 1899. 



Diagnosis. — Rostrum with a pair of spines midw\ay of its length. 

 Hepatic spine much the longest. Eyestalks short. Legs filiform. 



Description. — Carapace ovoid, strongly narrowed in front, ending 

 in a sharp rostrum, directed forward and downward and surmounted 

 laterally by two strong spines; its tip reaches the flagellum of outer 

 antennae. At base of rostrum are two large supra-orbital spines 

 directed upward and outward. A very long spine, having the same 

 direction as the preceding, arms the hepatic region; behind this the 

 branchial lobe bears a very small spine, as does also the metagastric 

 lobe. The anterolateral spine is behind and longer than the antennal 



