180 Bulletin Vanderhilt Marine Museum, Vol. V 



Genus : PACHYGRAPSUS Randall. 

 Pachygrapsus minutus A. Milne Edwards. 



Plate 91. 



Type : Randall's type came from the Sandwich Islands, and was de- 

 posited in the Philadelphia Academy of Natural Sciences. 



Distribution: Hawaiian Islands, (Randall); Palmyra and Fan- 

 ning Islands, (Edmondson) ; Rotuma, (Borradaile) ; Ponape, Caroline 

 Islands, reef, (Rathbun) ; Praslin, Seychelles, Coetivy, (Rathbun) ; 

 Zanzibar, Bawi, East Africa, (Lenz) ; Maldives, (Borradaile) ; Mergui 

 Archipelago, (Alcock) ; Samoa, (Boone). Shadwin, Red Sea, (Balss) ; 

 New Caledonia, (A. M. Edwards) ; Banda Sea, Owen Island, Mergui 

 Archipelago, Pulo Edam and Noordwachter Islands; Bay of Bengal, 

 (de Man) ; Honolulu, (Cano) ; Laysan Island, (Rathbun). 



Material examined : Three males and two ovigerous females taken 

 on the reef at Apia, Samoa, September 5, 1931. 



Technical description : Carapace about one-fiifth wider anteriorly 

 than long, with the frontal margin deflected, slightly sinuous ; the post- 

 orbital angle acute, the lateral margins are sharply convergent poste- 

 riorly and have no spine except the postorbital spine. The orbits are 

 oblique, their long diameter about two-fifths of the width of the frontal 

 border ; the orbital margins are smooth. The dorsal surface of all five 

 specimens is glabrous, devoid of transverse and oblique lines. 



The chelipeds are equal in both sexes but are more massive in the 

 males ; the carpus has an acute spine at the inner angle ; the palm is 

 short, stout and high, with the outer surface very convex, smooth, the 

 lower finger is about one-third of the total propodal length, thick, with 

 the cutting edge regularly serrate ; the tip rounded and hollowed in- 

 wardly and fringed with bristles ; the upper finger is decidedly down- 

 curved, its hollowed, rounded tip meeting upon that of the lower 

 finger ; the cutting edge finely serrulate ; a slight elliptical gape occurs 

 between the two fingers. 



The ambulatories are quite long, increasing in length from the first 

 to the third pairs, the fourth pair being subequal to the second pair ; 

 each has the meral joint widened, with both lateral margins with a 

 small, acute, subdistal spine; the dorsal meral surface is transversed 

 by numerous fine wavy ridges ; the carpus and propodus are less wide 

 and thicker, while the dactyl is stout, about two-thirds as long as the 

 related propodus and sharp-tipped. There are numerous solitary, 

 sharp slender spines on the inferior lateral margin of the propodus and 



