7i 



Key to the species : 



i . Lateral margins of carapace archecl 2 



Lateral margins of carapace subparallel Gr. intermedius cle Man 



2. Front much deflexed and high i'heisfht half the breadth between 



Cf V ö 



eye-stalks). Epistome long. Tooth at inner angle of orbit obtuse. 



Walking legs, at least propodites, elongate Gr. maculatus Catesl 



Front less deflexed and less high (height always less than half 

 the breadth between eye-stalks). Epistome shorter. Tooth at 

 inner angle of orbit subacute, keeled. Walking legs shorter. G. strigosus (Herbst) 



1 . Grapstis strigosus Herbst. PI. 4, Fig. 1 and 4. 



Literature and description : ALCOCK : 1. c. p. 393 '). 



Stat. 34. Labuan Pandan, Lombok. 2 cf (1 juv.), 1 $. 



Stat. 51. Madura Bay, Molo Strait. 1 9. 



Stat. 60. Haingsisi, Samau Island near Timor. 1 (f. 



Stat. 61 a. Adonare Island, east of Flores. 1 9- 



Stat. 231. Ambon. 2 Q. 



The specimens are of moderate or small size. 



Though the differences between the present species and Graftsus maculatus are well 

 enumerated by Alcock, the examination of a large series of specimens of the Leiden Museum 

 induced me to sum up the following points, for the help of those who have no opportunity 

 to compare both species. 



Grapsus maculatus. 



36- — 3/°/ °f distance betw. ext. orb. 



angles 

 One-half of its breadth betw. eye- 



stalk 

 With two symmetrically-placed larger 



tubercles 

 Obtuse 



One-third of its breadth 

 More than twice as long as broad 



Breadth of front 

 Height of front 

 Surface of front 



39—40" 



Grapsus strigosus. 



of the said distance 



Inner suborbital tooth 

 Length of epistome 

 Meropodites of walking legs 



Length of carpo- 4- propodite Distinctly longer than meropodite 



of penultimate pair of legs of this leg 4 ) 



Length of first pair of walking Much shorter than that of last pair 



legs 



Distal part of posterior margin Usually not dentate, obscurely so in 



of meropodite of last pair very large individuals 



Less than 'one4ialf of its breadth 



betw. eye-stalks 

 Without such tubercles 



Subacute, keeled 



Scarcely one-fourth of its breadth 



Twice as long as broad 



Equal to or slightly exceeding length 



of meropodite a ) 

 About equal to that of last pair 



Dentate as in the preceding legs 



1) Arch. Naturgesch., Jahrg. 53, I. p. 365, pi. 16, f. 1. Hab. Noordwachter Island (Bay of Batavia). Though this species is 

 indeed closely related to Gr. strigosus it is apparently a distinct species, that does not at all attaiD the large size of Herbst's species 

 (breadth of carapace at most about 20 ram.). 



2) Literature~~and description : Alcock, 1. c. p. 392. This species has often been called Grapsus grapsus owing to its having 

 been designated by Linné under the name Cancer grapsus. Distributed throughout all tropical regions, but chiefly Atlantic. 



3) To the synonyms enumerated by Alcock Grapsus longipes Stimpson should be added (Miss Rathbun in footnote of STIMPSON's 

 memoir (Smithson. Inst., Miscell. Coll., v. 49, 1907, p. 119). This species is wholly Indo-Pacific. 



4) See PI. 4, Fig. 2. 



5) See PI. 4, Fig. 1. 



71 



