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



third longer than the merus, and both possess a raised inner margin which carries a 

 fringe of hairs ; the merus is slightly granulated, and furnished with a strong fringe of 

 hairs on the outer border; the three terminal joints are of very small size, and inserted 

 opposite a slight depression near the end of the merus ; the exognath extends to the end 

 of the ischium. The thoracic sternal region is smooth and polished, with a depression 

 opposite the second pair of legs, and an acute granular projection on each side between 

 the basal joints of the first and second legs. 



The chelipedes are more than half the length of the carapace ; the ischium with a 

 small acute spine on its anterior border ; the merus dilated and smooth, except on its 

 inferior surface, where it is slightly granulated ; the carpus about half the length of 

 the merus, with two anteriorly directed sjjines on its upper surface (of which the 

 external is larger) ; the propodus is somewhat flattened, with a single curved spine 

 above, and three on the lower edge, the immobile finger is set nearly at a right angle to 

 the main body of the propodus, and its inner edge is dentate ; the dactylus is entire, 

 slender and acute. The ambulatory limbs are smooth and polished, increasing in size 

 from before backwards till the penultimate pair is reached ; the propodus of the first and 

 second pairs is produced into a rounded anterior lobe which is absent from the third pair, 

 but these last have a well-marked posterior lobe ; the dactyli are somewhat ovoid, those 

 of the first and second pairs with acute apices ; the legs of the third pair are fringed with 

 hairs (especially their dactyli and propodi), the two anterior pairs are more sparsely 

 clothed. The last pair of legs are about half the length of the penultimate pair, with 

 the propodus and carpus subequal ; the dactylus is very minute and scarcely curved. 



The abdominal segments are smooth and polished above, ciliated laterally ; they 

 diminish in size gradually from before backwards. In the male the vasa deferentia are 

 continued externally as tubular prolongations on both sides ; the anterior pair of genital 

 appendages are long, and their terminal joints curved, the second pair less than half the 

 length of the first. The abdominal appendages in the female are strongly ciliated. 



An adult male gives the following measurements: — Breadth of carapace 12 '7 mm., 

 length of carapace 23 "5 mm., of fronto-orbital margin 8*5 mm., of chelipede 18 mm., of 

 last leg 9 '5 mm., of external maxilHpede 9 mm., of abdomen 8 '3 mm., of anterior genital 

 organ 9 mm. 



The British Museum collection contains specimens of this species from the Eastern 

 seas, named (but never described) by Adam White ; I have in the foregoing account 

 adopted his manuscript name. In Raninoides laevis (Latr.), the fronto-orbital border 

 has the lobes more strongly marked, drawn out into teeth, and the intervening fissures 

 deeper ; the lower border of the hand also is armed with many spines. The West Indian 

 Raninoides nitidus, A. Milne-Edwards, has the lateral border armed with two spines 

 behind the antero-lateral angle. 



Habitat. — Amboina; 15 fathoms. Several specimens, representing both sexes. 



