TO INDIAN CARCINOLOGT. 413 



{Heller) ; Sooloo Sea (Dana) ; New South Wales (Dana, Hess). Krauss records the 

 species from Natal, and Eichter records it from Madagascar, but their specimens were 

 perhaps referable to some other Diogenes *. 



208. Diogenes merguiensis, De Man. 



J), merguiensis, De Man, Mergui Crust, p. 228, pi. xv. figs 4-6 (1888). 



Muttuwartu Par, an adult male (Thurston) ; not uncommon at Madras (J. B. H). 



This species has been so fully described by De Man that only the more important 

 differences between it and the foregoing species— to which undoubtedly it is closely allied — 

 need be pointed out. The ophthalmic process is narrow and slender, but not twice the 

 length of the ophthalmic scales ; it ends in a pointed spine and is sparingly provided with 

 lateral spinules, which appear to arise from the dorsal surface. The eye-stalks, antennal 

 and antennular peduncles, are comparatively shorter than those of D. Diogenes. The 

 ophthalmic scales are somewhat narrow, with the marginal spinules rather prominent 

 towards the apex. The antennal acicle is deeply cleft, the outer process passing beyond 

 the distal end of the penultimate peduncular joint, while the inner process scarcely extends 

 so far; both processes are sparingly spinose on the inner margin. The antennular 

 peduncle exceeds that of the antenna only by about one-fourth of its last joint. 



The chelipedes and ambulatory legs are covered with short hairs or setae, which in most 

 places radiate from tubercles. The hand of the left chelipede is short and broad, and 

 the outer surface is covered with subacute setigerous tubercles, which are somewhat 

 deficient on the immobile finger. The upper margin of the whole chelipede is distinctly 

 spinose. The anterior margin of the ambulatory legs is also spinose, the spines being 

 most strongly developed on the carpi ; the dactyli are shorter and less strongly curved 

 than those of D. Diogenes, with the posterior surface hollowed out from side to side, and 

 the spinules of the anterior margin almost obsolete. 



The largest specimen I have seen was 53 mm. in total length. In a young specimen 

 only 14 mm. long, all the distinctive features are recognizable, but as usual there is 

 a tendency to exaggerated spinulation. 



Although this is perhaps the species figured by Milne-Edwards as Pagurus miles 

 (Ann. Sci. Nat. ser. 2, Zool., t. vi. pi. xiv. fig. 2, 1836), yet his description applies much 

 better to D. Diogenes. 



Distribution. Mergui (De Man). 



209. Diogenes miles (Herbst). 



Cancer miles, Herbst, Naturges. Krabben u. Krebse, Bd. ii. Heft 1, p. 19, Taf. xxii. fig. 7 (1791). 



Pagurus diaphanus, Fabricius, Suppl. Eut. Syst. p. 412 (1798) ; Milne-Edwards, Hist. Nat. Crust, 

 t. ii. p. 236 (1837). 



Banieswaram and Silavaturai Par (Thurston) ; common at Madras (J. B. H.). 



This species lives invariably in shells with a narrow aperture, and its marked peculi- 

 arities of form are due to this fact ; at Madras it is nearly always found in Olim shells, 

 and the adult, so far as I know, always selects the shell of Olioa gibbosa, Born. The 



* In the British Museum collection there are examples of a large and perfectly distinct species from Natal. 

 SECOND SERIES.— ZOOLOGY, VOL. V. 59 



