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



Munidopsis brevimana, Henderson (PI. XVII. figs. 1, 2). 



Munidopsis brevimana^ Henderson, Ann. and Mag. Nat. Hist., ser. 5, vol. xvi. p. 414, 1885. 



Characters. — The carapace is glabrous and covered with short transverse ridge-like 

 elevations, which exist in greatest number on the posterior half ; in some specimens also 

 short hairs are sparingly met with. The gastric area is swollen, and armed in front with 

 two prominent spines placed behind the base of the rostrum, while the short transverse 

 ridges are comparatively few in number ; the cardiac area is circumscribed, and a deep 

 furrow crosses it transversely near the middle ; the ridges are strongly marked, and 

 lengthen out somewhat on the branchial regions. The rostrum is narrow and acute, 

 slightly elevated towards the apex, and carinated superiorly, its length being less than 

 half that of the carapace. The lateral margin of the carapace is armed with five spines, 

 three of which are situated between the two divisions of the cervical groove, and the 

 first of this trio reaches the greatest size ; a single spine is placed on the antero-lateral 

 margin behind the antennal peduncle; the posterior margin is prominent, but unarmed. 



The ehelipedes are stout and remarkably short, with the joints pubescent, and the 

 merus and carpus somewhat spiny above. The lower surface of the ischium is produced 

 anteriorly, and a spinule is present near the apex of this process ; the propodus is almost 

 smooth, and dilated both from side to side and from above downwards'; the fingers are 

 short and stout, with their opposed surfaces deeply excavated, and the apical margins 

 finely toothed; numerous short tufted hairs are present towards the apices, and the outer 

 surface of the immobile finger carries a denticulate carina. The ambulatory limbs are of 

 moderate length, and the posterior surfaces of the meri and carpi are tuberculate, while 

 their anterior margins are strongly spinose; the posterior^ surface of the propodi is 

 carinated ; the dactyli are only curved towards the apex, and their posterior margins are 

 denticulate, the teeth increasing in size towards the terminal claw. 



The eyes still retain a certain amount of mobility, and are separated ventrally 

 by from one to three small calcified pieces ; the cornea is rounded, and the peduncle is 

 prolonged into two slender lateral spines, the inner of which is about twice the length of 

 the other. The antennal flagellum is more than twice the length of the body. The 

 merus of the external maxillipedes has its inner margin irregularly dentate. 



The abdominal segments are comparatively smooth, a few granulations being present 

 merely on the posterior ones ; the second, third, and fourth each bear a curved transverse 

 sulcus, the convexity of which is directed forwards. 



This species is allied to Munidoims reynoldsi (A. Milne-Edwards), dredged by the 

 "Blake" ofi" Frederickstadt, West Indies, at the great depth of 2376 fathoms. The 

 latter is of small size, its ehelipedes are considerably shorter, and more than two spines 

 are situated on the gastric region of the carapace. 



