170 CEYLON PEARL OYSTER REPORT. 



Localities. Gulf of Manaar ; several specimens from Kondatchi Paar, one specimen 

 from Periya Paar Kerrai ; depth, 8 to 9 fathoms. 



This new species resembles a little in general form the C. austral is of Sars, but 

 differs from it and from all the species of Cyclaspis hitherto described not only in 

 the longitudinally-ribbed carapace, but also in the shortness of the first legs, the 

 short abdomen, especially of the female, and in the stoutness and armature of the 

 uropods. In the fact that the first leg-bearing somite is distinct in the female, it 

 agrees with the species described below, but no other species is yet known in which 

 this somite is exposed in the male also. 



Cyclaspis picta, n. sp. Plate III., figs. 54 and 55. 



Description of Female with rudimentary oostegites. Total length, 3 millims : 



The carapace is a little more than one-third of the total length and is somewhat 

 compressed, the dorsal surface keeled, especially in front. Seen from the side, 

 the dorsal edge is evenly arched, the pseudorostrum is prominent and sharply 

 triangular, the lateral plates meeting in front of the ocular lobe for a distance equal 

 to the transverse diameter of the latter. Antennal notch widely open, antennal tooth 

 sharp, with a spiniform point. Ocular lobe of moderate size, acuminate anteriorly, 

 not sharply constricted off from cephalic lobe, eye well pigmented, corneal lenses not 

 distinct. The sides of the carapace are quite smooth, devoid of ridges or tubercles. 

 The texture of the exoskeleton is (in this specimen) regularly reticulate, with a faintly 

 indicated shallow pitting over the whole of the carapace. 



First leg-bearing somite well exposed, but apparently firmly united to the carapace, 

 the suture line being somewhat faintly shown. 



Abdomen rather slender, nearly equal in length to the cephalothoracic region, the 

 somites sub-cylindrical, with well-marked articular processes laterally. 



First legs comparatively short, extending beyond the antennal tooth by little more 

 than the terminal segment. Second legs with the ischium distinct. 



Uropods (fig. 55) having the peduncle nearly twice as long as the last somite and 

 more than twice as long as the rami, which are sub-equal, the endopod especially 

 rather broad and flattened, tipped with a spine, and having two spines on its serrate 

 inner edge. The exopod has a terminal spine and a small spinule close to it on the 

 outer side. 



Both the specimens show a peculiarly shaj^d pigment patch on the carapace. The 

 last thoracic and some of the abdominal somites are also pigmented. 



Locality. Gulf of Manaar, Cheval Paar ; depth, 7 fathoms ; 2 specimens. 



This form belongs, with the two following, to a group of species characterised by 

 the smoothness of the carapace and including C. longicaitdata, Saks ; C. pusilla, 

 Sars ; C. levis, Thomson ; and C. argus, Zimmer. From all of these it seems to be 

 sufficiently distinguished by the presence of five distinct thoracic somites, by the 

 acute pseudorostrum, and by the much longer peduncle of the uropods. 



