804 THE VOYAGE OF H.M.S. CHALLENGER. 



posterior pair the dactylos is embedded ; the carpos is long, slender, and cylindrical, being 

 about fourteen times longer than the propodos, and nearly as long as the meros and 

 ischium united ; these two joints are united by a long overlapping articulation, and are 

 both fringed with spine-like teeth, and the meros is armed with a strong tooth at the 

 anterior distal angle that projects above the carpal articulation. 



The telson equals in length the inner branch of the rhipidura, and is smooth and 

 unarmed. 



Observations. — This species appears to be the most common form ; the females carry 

 a considerable number of small round ova. The specimens taken at Station 200 were 

 numerous, and were associated with several other genera, such as Pontophilus, Hetero- 

 carpus, Solenocera, Palwmonella, &c. Three of the specimens here taken were attacked 

 by a species of Bopyrus. 



The three specimens taken at Station 171 differ in size and in some minor points 

 from the others, but belong I believe to this species. They are all males and are larger 

 than the largest female taken elsewhere, measuring 113 mm. The carapace is 31 mm., 

 and the rostrum 9 mm. long. They are also furnished with twelve or thirteen points on 

 the frontal crest and upper margin of the rostrum, and with one small one near the apex 

 on the lower margin, which appears to be a feature more common in the males than 

 females, although seen in some of these also, and when not present the rostrum is thicker 

 towards the apex, which is perhaps its normal condition. 



The female specimen taken at Station 194 has the subapical tooth on the under 

 margin of the rostrum developed into a strong and well-formed denticle, and much more 

 conspicuous than in any of the numerous specimens which are typical in form from 

 other localities. 



This species differs from Nematocarcinus gracilis chiefly in having a less number of 

 teeth on the upper surface of the rostrum. 



Nematocarcinus lanceopes, n. sp. (PL CXXXL). 



Rostrum projecting anteriorly, nearly as long as the carapace, armed on the upper 

 surface with a series of very small teeth, about twenty-six in number, and on the lower 

 with eight teeth and no fringe of cilia. 



Ophthalmopoda short and embayed in a deep orbital notch, which is armed at the 

 outer angle with a sharp antennal tooth. 



First pair of antennse having the peduncle about half the length of the rostrum ; first 

 joint excavate to receive the ophthalmopoda and the other two short and cylindrical ; the 

 flagella are long and slender, the outer being a little larger at the base than the inner. 



Second pair of antennse carrying a scaphocerite that is nearly as long as the rostrum, 

 and a long and slender flagellum. 



