i85 



scattered, even on the dactyli. The last pair of legs is peculiaiTy transformed: the 

 carpo- and especially the propodite are rather much flattened, so as to form a swimming paddie; 

 the latter joint is indeed broader than half the length of the anterior margin (Rathbun); the 

 dactylus is perfectly straight, not curved near the tip, flattened, but not considerably broadened. 

 All three named joints are fringed with feathered hairs (fig. if), generally as long as the breadth 

 of the joint to which they are attached, but longer on the inner margin of the propodite, and 

 on the inner margin of the dactylus decreasing in length from base to tip ; the outer margin 

 of the dactylus bears numerous feathered hairs of about equal length, between which are placed 

 a few ordinary hairs. 



The abdomen of my larger cf specimen (fig. i d) differs somewhat from that figured by 

 Miss Rathbun in being considerably broader from the 4* segment to the tip; in other points 

 there is a general agreement : the i^' segment is hidden under the carapace (in my figure it 

 is exposed, on account of the abdomen being severed from the cephalothorax), the 2"<^ segment 

 is as broad as the following and both entirely cover the last segment of the 

 sternum. As has been said the rest of the abdomen of Miss Rathbun's specimen is very 

 narrow, the last segment being much longer than broad, whereas in my specimen the abdomen 

 resembles that of G. simiatifrons in being considerably wider, the terminal segment presenting 

 about equal dimensions in length and along the base. 



Notwithstanding small discrepancies between the descriptions there can be no doubt as 

 to the identity of my specimen with Miss R.\thbun's, the differences being easily accounted for 

 either by the difïerent size of the examples or to individual variations. The shape of the 

 carapace with its rectangular, not prominent external orbital angle, foliowed by an acuminate 

 epibranchial tooth. and the transformation of the last pair of legs into swimming paddies afford 

 excellent specific characters. 



Miss Rathbun's specimen was caught at Gan Island, Addu Atoll, Maldive Arch. 



For completeness' sake I add the measurements of this former example. 



Dimensions in mm. : 



Distance between external orbital angles . 



Breadth of front 



Distance between tips of epibranchial teeth 



Length of carapace 



Length of meropodite ] 



Breadth of meropodite f 



Length of carpo-and propodite together 



Length of dactylus 



Length of meropodite 



Breadth of meropodite. 



Length of carpo-and propodite together 



Length of propodite along anterior margin 



Breadth of propodite 



Length of dactylus 



of peoultimate pair of legs 



of last pair of legs 



vt^J 



N" I is the "Siboga" specimen, n" 2 that of Miss Rathbun. 



37 



