TO INDIAN CAECINOLOGT. 30 



)U 



excavated; tlic upjiev oibitnl niaigin is granulated and has two well-marked fissures. 

 The granulated lobes on the carapace are arranged as follows :— on the anterior gastric 

 region, behind the front, two pairs, of which the posterior is much larger; on the 

 posterior gastric region three lobules, one median and anterior, two posterior ; on each 

 protogastric or lateral gastric region a peculiar Vi/ -shaped lobule; on the cardiac region 

 two lobules which are slightly excavated in the centre; on the branchial region three 

 lobules, anterior, postero-exteiaial (which is the largest of the threi;), and a postero-intcrnal 

 one placed external to and bctAvet n the jjosterior gastric and cardiac lobules. 



The right chelipede is sliglitly larger than the left in both sexes; both are clotlied 

 Avith a short pubescence on the (inter surface of the carpus and hand, except towards the 

 base of th(> immobile finger. The carpus is sparingly tuberculate externally, Avith a 

 sulcus running parallel to the articulation with the hand, and separated from the latter by 

 a tuberculated strip ; the outer surface of the hand is strongly tuberculate, the tubercles 

 with more or less acute apices, rather closely crowded and Avithout any definite arrange- 

 ment. The fingers are short, with Avhite and obtuse ti2)s, and the immobile! one is placed 

 in a straight line Avith the lower border of the hand ; the dactylus is tuberculated 

 superiorly on its proximal half, and a prominent tooth is present on either finger. The 

 ambulatory legs are simply pubescent. The abdomen is smooth and seven-jointed in 

 both sexes. The external raaxillipedes are smooth, AAith a faint impressed line in the 

 middle of the proximal two-thirds of the ischium. The basal joint of the anteimal 

 peduncle is joined to the subfnmtal process, and the terminal joints lie in tlie orbhal 

 hiatus. 



The largest specimen (a male) has the carapace ]8'5 mm. long and 'liy-'i mm. broad, 

 the lower margin of the hand and immobile finger 18 mm., mobile linger 9"7 mm., height 

 of hand IT'.j mm. There is great disparity shown in the size of adult females (carrying 

 ova) from the same locality — the largest is 18 mm. long and 25 mm. broad, while the 

 smallest is 9 mm. long and 11-5 mm. broad. 



This Avell-marked species in general appearance comes nearest to A. (jlohi<lits, Itellei-, 

 from the Red Sea and Zanzibai', but the latter lias the carapace differently lobulated 

 and the antero-lateral margin with only three projections. 



Genus PiLUMNTJS, Leach. 



81. PlLUMNUS VESPEKTILIO (Fabr.). 



P. vesperfi/io (Fahr.), Micrs, Ann. Mag. Nat. Hist. ser. 5, vol. v. p. :234 (1880), i/di si/hmi. 



(= P. la-.iiihi.f, Adams & "White, P. nms, Daua). 



Rameswaram and Tuticorin, many specimens {Thurston); Ceylon {Rolif); Rames- 

 waram, very common on the reef and between tide-marks {J. B. H.). 



Distribution. Prom the Red Sea and E. Africa to Japan, Australia, and the Pacific. 



82. PiLUMNUS LABYKiXTHicus, Miers. 



p. luhyrinmms, Miers, ■ Alert' Crust, p. 221, pi. xxii. fig. C (ISSl). 

 RamesAvaram, a single specimen {J. B. S.). 



SECOND SERIES. — ZOOLOGY, VOL. V. 53 



