There are two small Grapsi in the ''Siboga"-collection, both cf, one collected at Stat. 19 

 (Labuan Tring, west coast of Lombok), the other at Stat. 277 (Dammer Island, Banda Sea). 

 The first named, though the smaller one, is more perfect and has been figured on PI. 4. Fig. 4. 

 I regard, though with some doubt, these specimens as Grapsus longitarsis. In the original 

 specimen of Dana the legs are apparently wrongly figured ^), the dactyli being represented 

 stunted and as long as the short propodites. 



The lateral margins of the carapace in my specimens are nearly parallel, especially 

 in the smaller individual. By this character they approach Grapsus intermedhis ^ in which, 

 according to de Man, the ambulatory legs are comparatively much shorter. On the whole the 

 carapace and especially the breadth and shape of the front is wholly like that of Grapsus 

 strigostts, but the walking legs are much more elongate; the difference in size between the 

 first and fourth pair is distinctly pronounced, and the meropodites are 2^l„ times as long as 

 broad and narrowing distally. The length of the penultimate pair of legs is more than 2^3 times 

 the length of the carapace (twice its maximum breadth), whereas in typical specimens (of 

 slightly larger size) of Grapsus strigosiis this pair of legs is scarcely twice the said length ; the 

 carpo- and propodite together are nearly ecjual to the maximum breadth of the carapace, and 

 the propodite is slender, 4 — 4Y., times as long as broad, and distinctly longer, than the dactylus. 

 The upper margins of the meropodites in the first to third pair present a 

 few movable spines, which I do not observe in somewhat larger individuals of Grapsus 

 strigosus. Mero-, carpo- and propodite of the legs are crossed by more or less distinct trans- 

 verse stripes of a brown colour; in the smaller individual each joint has two of these stripes, 

 in the larger they are broader, almost confluent, and the meropodites are irregularly marbled. 

 The abdomen of the cf has the broad, equilaterally-triangular shape, described by Miss Rathbun, 

 but the same is observed in young specimens of genuine Grapsus strigosus. A hairy-edged 

 cavity between the bases of the second and third ambulatory leg is distinctly seen. 



The specimens may be characterized b)' having the carapace of Grapsus strigosus 

 and the legs of Grapsus maculatus and for this reason I refer them to Grapsus longitarsis. 

 Miss Rathbun states, that in this species (which I prefer to maintain as a subspecies of Grapsiis 

 strigostis) the front is wider, though she does not give us exact measurements to verif\' this ^), 

 and in my larger specimen the breadth of the front is 40 °/^, in the smaller individual even 

 43 °/o '-'^ '■^^ maximum breadth of the carapace (in typical Grapsus strigosus 39 — 40 °/^). 



Dimensions in mm. : 



Breadth of carapace 



Distance between external orbital angles .... 



Length of carapace 



Breadth of front between eye-stalks 



Length of meropodite of penultimate pair of legs 

 Breadth of meropodite of penultimate pair of legs 



1) U.S. Expl. Exp., Crust., 1852, pi. 21, f. 4a. 



2) Neither are such aieasuremeats giveo of the large specimen from the Indian Ocean (Egmont Reef) in her paper on the 

 marine Br.ichyura of the Percy Sladen Trust Expedition (Transact. Linn. Soc. London (2) v. 14, 1911, p. 241. 



73 



SIBOGA-EXPEDITIE XXXIXC. ■ 'O 



