414 



CEYLON PEARL OYSTER REPORT. 



(4) correlated with (3) is the short postero-lateral border of the carapace ; (5) the 

 middle region of the posterior border of the arm is considerably expanded the inner 

 surface of the hand and of the fixed finger is granular, and the under surfaces of all 

 segments of the cheliped have a glazed appearance ; (6) walking legs 1, 2, and 3 are, 

 as a whole, glazed, there are a few hairs along the upper border, walking leg 4 is 

 more or less tomentose. 



Remarks. The new species is distinguished at a glance from all other members of 

 the sub-genus by its very characteristic last pair of lateral spines. It will be noted 

 from (5) above that the cheliped bears a considerable resemblance to that of Neptunus 

 (Achelous) granulatus (H. MILNE-EDWARDS). 



I append the measurements of three adult males : 



Lat. sp. (post. Front. Front.orb. 

 U.l. u.b. -f-O.l. 



bord.)-:-C.l. b. -i-C.l. 



(a) . . 12-50 1-64 0'46 0'36 



(n) . . 13-00 1-58 0'54 0'38 



(o) . . 13-00 1-58 0-50 0-37 



Ant.lat. Post.lat. Post. 



b.-rC.l. bord.-5-C.L bord.-=-C.l. bord.-rC.l. 



0-88 0-68 0-32 0'56 



0-85 073 0-37 0'58 



0-85 073 0-33 0'58 



Antero-lateral border is from outer angle of orbit to notch between teeth 8 and 9. 

 Postero-lateral border is from base of posterior border of large spine to point of 

 junction with abdomen. 



Neptunus (Hellenus) hastatoides (FABRICIUS, 1798) A. 4, p. 38. Text-fig. 8. 



Localities : Galle, one specimen ; pearl banks, Gulf of Manaar, nine specimens ; 



off Mutwal Island, two specimens ; coral reefs, 

 Gulf of Manaar, twelve specimens ; Palk Bay, 

 two specimens. 



Description: C.I. of an ovigerous female 

 = 18-0. 



Remarks. LANCHESTER gives some account 

 of sexual differences obtaining in this species. 

 In view of the specimens before me I judge 

 his figure (' Proc. Zool. Soc.,' 1900, p. 745, 

 pi. xlv., figs. 7 a, 76) of a female abdomen to 

 be evidently that of a young example. It 

 agrees well with that of the young males of 

 the present collection (see text-fig. 8). 



Neptunus (Hellenus) hastatoides (FABRICIUS), var. unidens, nov. 



Locality : Coral reefs, Gulf of Manaar, one specimen. 



Description: A male, doubtfully adult, both chelipeds missing, C.I. = 12 '25. 

 This specimen differs from other specimens of N. hastatoides known to me in the 

 following particulars : 



Fig. 8. Growth stages in abdomen of Neptunus 

 hastatoides upper row males, lower three 

 females. 



