260 CEYLON PEARL OYSTER REPORT. 



Abdomen 3-jointed, the 1st joint being produced as in the other species of the 



genus, but different from them in having 4 large denticulations on its outer surface. 



Anterior antennas 7-jointed, the proportionate lengths of the joints being as 



, .. 1. 2. 3. 4. 5. 6. 7. 



tallows : - 



14. 10. 6. 4. 4. 4. 5. 



The 2nd maxillipeds differ considerably from those of any of the preceding species. 

 The middle joint is long and narrow, arcuate on one side and flat on the other, with 

 short seta? on one-half of the flat side. The terminal spine is shaped like a scythe 

 and about f the length of the middle joint. Natatory legs as in T. imthurni, 

 excepting 4th and 5th pairs. In the 4th pair the outer and inner branches are both 

 3-jointed, and the basal joint of the inner branch is not foliaceous. The 5th legs are 

 less angular than those of the other species, the surface being covered with rows of 

 convolute markings. 



Two sjsecimens, both females, were found in the Muttuvaratu pearl oyster 

 washings. The anterior antennas, the 2nd maxillijseds, and the 4th natatory legs 

 readily distinguish this species from the others of the genus. 



This species is named after Dr. A. J. Chalmers, formerly a Liverpool Student of 

 Science, now Registrar and Professor in the Medical College, Colombo. 



Stenhelia brevicornis, n. sp. — Plate V.. figs. 1 to 9. 



Length, female, 0"9 millim. ; male unknown. 



Cephalothorax narrow, 5-jointed. Anterior antennas short, 8-jointed, the relative 



1 2 3 4 5 6 7 8 

 lengths of the joints being as follows : Most of the joints 



J & 18. 12. 10. 8. 3. 4. 6. 12. J 



are shorter than the breadth and bear numerous setae. The 4th joint is produced on 



upper side, terminating in a long filament. 



Posterior antennas, mouth organs, and 1st to 4th pairs of natatory legs as in S. ima. 

 I he basal joint of 5th pair is large and triangular, bearing 6 marginal and apical 

 setas, two of them plumose ; second joint long and narrow, tapering towards apex and 

 bearing six setas, the apical one much longer than the marginal ones. Abdomen 

 5-jointed ; the posterior margin of the 1st joint has a dorsal hook, the margins of the 

 other joints being fringed with fine hairs. Furcal rami about 3 times as long as 

 broad. 



Two specimens only, both females, were found in the Muttuvaratu pearl oyster 

 washings. The short, broad-jointed anterior antennas, the outer joint of the 

 5th natatory legs, and the long furcal rami are the chief distinguishing features of 

 this species. 



Stenhelia gracilicaudata, n. sp. — Plate V., figs. 10 to 15. 

 Length, female, - 67 millim. ; male unknown. 

 Cephalothorax 5-jointed, very robust. Anterior antennas 8-jointed, the propor- 



