71 



Kej- to the species : 



1. Lateral margins of carapace arched 2 



Lateral margins of carapace subparallel Gr. infcj'inediiis de Alan ^) 



2. Front much deflexed and high (height half the breadth between 



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



Walking legs, at least propodites, elongate Gr. viaculatus Catesby -) 



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) 



I. Grapsiis sfrigosiis Herbst. PI. 4, Fig. i and 4. 



Literature and description: Alcock : I.e. p. 393^). 



Stat. 34. Labuan Pandan, Lombok. 2 ^ (i juv.), i 9- 

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

 iStat. 60. Haingsisi, Samau Island near Timor, i cf.. 

 Stat. 6ia. Adonare Island, east of Floras, i 9- 

 Stat. 231. Ambon. 2 9- 



The specimens are of moderate or small size. 



Though the differences between the present species and Grapstis viaailains 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 maciilatits. 



36 — 37° 'o of distance betw. ext. orb. 



Breadth of front 

 Height of front 

 Surface of front 



39—40" 



Grapsns strigosns. 



of the sa:id distance 



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 

 Distinctly longer than meropodite 

 of this leg ^) 

 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 ; Dentate as in the preceding legs 

 of meropodite of last pair j very large individuals | 



Inner suborbital tooth 

 Length of epistome 

 Meropodites of walking legs 

 Length of carpo- -j- propodite 

 of penultimate pair of legs 



Less than one-half 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 ') 

 About equal to that of last pair 



1) Arch. Naturgesch., Jahrg. 53, I. p. 365, pi. 16, f. I. Hab. Noordwaclilev 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 attain the large size of Herbst's species 

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



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

 been designated by LiNNE under the name Cancer grapsus. Distributed throughout all tropical regions, but chiefly .'Ktlantic. 



3) To the synonyms enumerated by Alcock Grapsus longipes Stimpson should be added (Miss Rathevn 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. I. 



71 



