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



pterygostomial region terminates anteriorly in a very minute spinule, and a depression 

 is visible towards its middle. 



The clielipedes are slender and elongated, with the joints smooth and glabrous. A 

 row of four or five small tubercles occurs on the inner proximal end of the merus, and a 

 few tubercles of smaller size are sometimes found on the inner surface of the ischium, 

 while a small spine is present on the upper and distal end of the same joint ; in some 

 specimens all the tubercles are nearly obsolete. The palm is but slightly dilated, and 

 not equal in length to the carpus ; the fingers are pubescent and excavated inferiorly, and 

 a single prominent tooth occurs on the inner margin of the dactylus. The ambulatory 

 limbs are smooth, with the exception of a few delicate spines on the posterior margin 

 of the propodi ; the dactyli are strongly curved, and about half the length of the 

 penultimate joints, with a series of minute horny spinules on their posterior margin. 



The eyes are of moderate size, and the cornese are light brown in colour. The 

 antennal aciele is slightly curved, and tapers gradually towards the acute apex, which 

 reaches almost to the end of the peduncle ; the flagellum is scarcely twice the length of 

 the peduncle (it is represented of too great a length in the figure). The external 

 maxilHpedes are unarmed. 



The abdominal segments are smooth and glabrous externally, and their pleura are 

 subobtuse. 



This species is closely allied to Uroptychus politus, from which it differs in the 

 following respects : — The gastric region of the carapace is more swollen in the former, 

 the rostrum is broader towards its apex, the chelipedes are more elongated, and finely 

 tubercular towards their bases, while there is no hiatus between the fingers, and the 

 antennal aciele is longer, more curved, and acuminate. 



The largest specimen (a female from Station 164) gives the foUowiug measure- 

 ments : — Breadth of carapace 7 mm., length of body (including rostrum) 21 mm., of 

 carapace (including rostrum) 10"5 mm., of chelipede 39 mm., of chela 15'5 mm., of first 

 ambulatory leg 18 mm. Diameter of ova, taken from another specimen, about 1 mm. 



Habitat. — Station 164b, ofi" Port Jackson; depth, 410 fathoms; bottom, green mud. 

 Two adult females, one with ova, and a young male. 



Station 170, ofi" the Kermadec Islands; depth, 520 fathoms; bottom, volcanic mud. 

 A female with ova. 



Station 171, near the Kermadec Islands ; depth, 600 fathoms ; bottom, hard ground. 

 A female with ova. 



Station 194a, ofi" Banda ; depth, 360 fathoms ; bottom, volcanic mud. A female with 

 ova, and two young individuals. 



