TO INDIAN CAECINOLOGY. 365 



excavated; the upper orbital margin 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 KV -shaped lobule; on the cardiac region 

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

 lobules, anterior, postero-external (which is the largest of the three), and a postero-internal 

 one placed external to and between the posterior gastric and cardiac lobules. 



The right chelipede is slightly larger than the left in both sexes ; both are clothed 

 with a short pubescence on the outer surface of the carpus and hand, except towards the 

 base of the immobile finger. The carpus is sparingly tuberculate externally, with a 

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

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

 with more or less acute apices, rather closely crowded and without any definite arrange- 

 ment. The fingers are short, with white and obtuse tips, and the immobile one is placed 

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

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

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

 both sexes. The external maxillipedes are smooth, with a faint impressed line in the 

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

 peduncle is joined to the subfrontal process, and the terminal joints lie in the orbital 

 hiatus. 



The largest specimen (a male) has the carapace 18*5 mm. long and 25*3 mm. broad, 

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

 of hand 1V5 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 well-marked species in general appearance comes nearest to A. globulus, Heller, 

 from the Red Sea and Zanzibar, but the latter has the carapace differently lobulated 

 and the antero-lateral margin with only three projections. 



Genus Pilumntjs, Leach. 



81. Pilumnus vespertilio (Fabr.). 



P. vespertilio (Fabr.), Miers, Aim. Mag. Nat. Hist. scr. 5, vol. v. p. 234 (1880), ubi synon. 



(= P. Ursulas, Adams & White, P. mus, Dana). 



Raincswarani and Tuticorin, many specimens (Thurston); Ceylon (Haly); Rames- 

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



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



82. Pilumntjs labyrinthicus, Miers. 



P. labyrinthicus, Miers, ' Alert' Crust, p. 224, pi. xxii. fig. C (1884). 

 Rameswaram, a single specimen (J. R. H.). 



SECOND SERIES. — ZOOLOGY, VOL. V. 53 



