78 • THE VOYAGE OF H.M.S. CHALLENGER. 



The uropoda are extremely small and closely attached to the sides of the abdominal 

 shield near to the posterior termination of the latter. They arc figured in position in 

 fig. 4, and one of the appendages, more highly magnified, is shown in fig. 5 of the 

 same plate; 1 the protopodite is of considerable length and bears two rami of which the 

 more distant is the larger, the latter being perhaps only doubtfully the equivalent of the 

 other rami, in which case, the appendages of this species evidently agree very closely 

 with those of other species, since they conform to the generic definition given above. 



Station 149h, off Cumberland Bay, Kerguelen, January 29, 1874; lat, 48° 45' S., long. 

 69° 14' E. ; depth, 127 fathoms; volcanic mud. 



Acanthocope, F. E. Beddard. 



Acanthocope, F. E. Beddard, Proc. Zool. Soc. Lond., 1885, pt. iv. p. 922. 



Two remarkable Munnopsids, both dredged in deep water in the southern hemi- 

 sphere, and the types of two distinct species, appear to me to necessitate the creation of 

 a new genus, which may be defined as follows : — 



Generic Characters. — General form of the body oval, no marked difference in breadth 

 between the anterior and posterior regions of the thorax. Anterior segments of the 

 thorax increase progressively in length ; the posterior segments of the thorax subequal ; 

 the general aspect of the thoracic segments as in Eurycope ; epimera of all the thoracic 

 segments from the second onwards, enormously elongated into curved sickle-shaped spines. 

 The abdominal shield oval, with a long terminal spine as long as or longer than the caudal 

 shield itself, and with two pairs of lateral spines, one more anterior, the second over- 

 lying the articulation of the uropoda. Antennae with the two basal joints furnished with 

 one or two long spines ; mandibles divided into several tooth-like processes ; molar pro- 

 cess stout and powerful, with a blunt edge suitable for crushing, palp small and three- 

 jointed. First pan- or first two pairs of legs shorter and more slender than the rest, the 

 two or three following pairs subequal and not greatly elongated. Posterior thoracic 

 appendages natatory, with flattened penultimate and antepenultimate joints, fringed with 

 long plumose setae. Uropoda long and styliform, three or five-jointed. 



Remarks. — The above generic definition necessarily applies to both the species which 

 I include within the genus, but the characters of the two species are, in many respects, 

 very unlike ; on the whole Acanthocope acutispina comes nearer to the other genera of the 

 family than does Acanthocope spinicauda. If it were necessary to assign the former species 

 to any one of the genera already described, it would probably be referred to Desmosoma. 



One of the most striking characteristics of the genus Desniosomo, viz., the shortness 

 of the antennae, I am unable to verify in the present genus, since in both species the 



1 The drawing has been accidentally reversed ; the point of articulation of the appendage is directed towards the 

 lower margin of the plate. 



