3(58 CEYLON PEARL OYSTER REPORT. 



Sarsiella carinata, n. sp. Plate I., figs. 1 and 2 ; Plate II., figs. 40 and 41. 



Shell membranous, thin and flexible, seen from the side subrhomboidal, height 

 equal to about two-thirds of the length. Anterior extremity truncate, and provided 

 with a prominent protuberance at the beginning of the dorsal curve ; posterior 

 narrower, deeply excavated, bounded above and below by prominent projections ; 

 dorsal margin boldly arched, highest behind the middle, whence it slopes rapidly 

 towards the large projection ; ventral margin nearly flat, except at the posterior end, 

 where it is deeply sinuated ; seen from above elongated, widest in the middle, width 

 considerably less than half the length ; anterior extremity narrow, emarginate ; 

 posterior wide, terminating in one median and two lateral protuberances. The dorsal 

 and ventral margins are in the form of a continuous ridge with radiating lines, two 

 longitudinal ribs of a similar structure run parallel to, but at a considerable distance 

 within the margins, both terminating posteriorly in protuberances ; ventral margin 

 adorned with four protuberances of various sizes ; in addition to these, there are two 

 between the ventral margin and the lower ridge and one on the surface of the lower 

 posterior projection. Surface of the shell marked with numerous circular depressions, 

 which have four or five short setae round the outside ; dorsal and ventral margins 

 ciliated; size, l'l millims. 



Three specimens, all males, were found in washings from deep-water dredgings off 

 Galle. The antennules have the characteristic dense brush of long fine hairs ; post- 

 abdomen with five marginal ungues, increasing in length from the first to the last, 

 which is about five times as long as the first ; margins spinulose. 



Sarsiella gracilis, n. sp. Plate I., figs. 3 and 4 ; Plate II., fig. 37. 



Shell membranous, thin and flexible ; seen from the side subcircular, height equal 

 to fully two-thirds of the length ; anterior extremity broadly rounded, crenate, with 

 a distinct notch near the middle ; posterior truncate, with a wide triangular process 

 above and below ; dorsal and ventral margins rounded, the former sloping rapidly at 

 its posterior end ; seen from above, oblong subovate, widest near the posterior end, 

 width slightly less than one-third of the length ; anterior extremity obtusely rounded, 

 posterior truncated, with a median process ; surface of the shell slightly ciliated, 

 covered with small impressed puncta ; anterior and ventral margins ciliated ; size, 

 l - 34 millims. 



Two specimens were found in a dredging from 100 fathoms, off Galle, and one in 

 the general washings from invertebrates from Gulf of Manaar. All were mature 

 females with ova. The postabdomen has three stout ungues with spinulose margins, 

 and three short plumose setae. 



Sarsiella similis, n. sp. Plate I., figs. 5 and 6 ; Plate 11., fig. 38. 



Shell thin and flexible, subcircular, height fully two-thirds of the length ; seen 

 from the side anterior extremity rounded, crenate, with a slight notch in the centre, 



