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Lateral margins of carapace parallel, except immediately 

 behind external orbital angle 7 



7. Infra-orbital ridge in c? regularly crenulate 8 



Infra-orbital ridge in rf subdivided into three elongate 



lobules ; the lateral one the longest ....... C. parvülus de Man 



8. Two obscure notches (sometimes only one) behind each 



external orbital angle C. intermcdius Ortmann x ) 



Lateral margins of carapace entire C. henshawi Rathbun -j 



1. Cyclograpsus parvülus de Man. 



1896. Cyclograpsus parvülus de Man. Zool. Jahrb., Syst., Bd 9, p. 350, Bd 10, 1898, pi. 32, f. 42. 

 1907. Cyclograpsus parvülus Rathbun. Mem. Mus. comp. Zool. Harvard Coll., v. 35, n n 2, p. 36. 



Stat. 64. Tanah Djampeah, Flores Sea. 1 Q. 



This specimen agrees nearty completely with those of de Man, but the inner part of the 

 infra-orbital ridge in my 9 is not entire, but consists of 5 small lobules, and the lateral portion 

 is likewise subdivided into 3 — 4 lobules, as de Man rightly remarked in the case of the Q. The 

 original specimens came from Atjeh ; aftervvards the species has been collected at the Paumotus. 



Nobili has described a subspecies [unidens) ') in which one epibranchial tooth is found 

 behind the external orbital angle and the posterior margin of the penultimate segment of the 

 abdomen of the cf is not straight, but concave forward. 



I retained the name of parvülus for this species, but de Man himself observed 

 afterwards 4 ), that his species should be considered at. most a subspecies of the Atlantic 

 C. occidentalis A. Milne-Edwards. 



Subfam. Plagusiinae. 



There are two well known genera belonging to this group : Plagusia and Percnou 

 (= Leioloplius), which are at once characterized by the stout antennulae being lodged in oblique 

 fossae of the front and visible in dorsal view. The middle segments of the abdomen are largely 

 coalesced in both sexes, the carpus of the external maxillipeds articulates near the antero- 

 external angle of the merus, and the lateral margins of the carapace are toothed. 



The two genera are at once distinguished by the following characters : 

 Carapace thick. Merus of external maxillipeds as broad as ischium . . . Plagusia Latreille 

 Carapace much flattened. Merus of external maxillipeds much smaller and 



narrower than ischium Perenon Gistel 



1) Zool. Jahrb., Syst., Bd 7, 1S94, p. 728. Hab. Indian Ocean. Loo-Choo Islands and Japan. Perhaps C.intermeJius is synonymous 

 to C. longipcs. 



2) Proc. U.S. Xat. Mus., v. 26, 1902, p. 75, textfig. 1—2; Buil. U.S. Fish Comm. for 1903, v. 23, pit 3, 1906, p. 840. Hab. 

 Ilawaiian Islands. 



3) Ann. Mus. Hung.. v. 3, 1905, p. 501. Hab. Berlinharbour, Geiman New Guinea. 



4) Mém. Soc. Zool. France, 1900. p. 57. 



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