400 CEYLON PEARL OYSTER REPORT. 



Remarks. This species is new to the Indian fauna. It may conveniently be 

 separated from all other Indian forms by having the edge of the antero-lateral border 

 of the carapace rounded in its anterior portion. 



Euxanthus herdmani, n. sp. Plate I., figs. 9, 9a. 



Locality : Pearl banks, Gulf of Manaar, one specimen. 



Description: An adult male. C.I. (including frontal lobes) = 23 '00. 



The lobules of the carapace are strongly convex, 2L more prominent than the 

 others ; they are dimpled, but 3M very slightly so ; there is a fine pitting on the 

 anterior part of the surface of the carapace, producing a dull appearance ; the posterior 

 part is glazed. The antero-lateral border is cut into four blunt tubercular teeth, the 

 hindermost of which is smaller than the other three, which are of sub-equal size ; the 

 sub-orbital continuation of the border is indistinct. The curve of the orbit is 

 unbroken by any denticle at the outer angle, and is seen by the lens to be finely 

 granular. 



The exopodite of the external maxilliped is granular, so is the outer proximal part 

 of the ischium and the free border of the merus. The longitudinal groove of the 

 ischium and that of the merus are both deep. The outer surfaces of the wrist and 

 hand, as of the corresponding segments of the legs, are nodular, both nodules and the 

 hollows between them being smooth. The outer surface of the wrist is rounded, with 

 the nodules faintly marked (by no means so obvious as in E. melissa or E. sculptilis). 

 The inner surface of hand, wrist, and arm is flattened and smooth ; the upper surface 

 of the hand has two nodules distally behind the finger joint, and a third posteriorly 

 just in front of the wrist joint. Running obliquely backward and outward from the 

 outer of the two distal nodules is a series of three others, from each of the first and 

 third of which runs forward a wrinkled non-granulated line. The fingers have 

 strongly toothed cutting edges, the distal end of the fixed finger is hollowed on the 

 inner side of the teeth ; the proximal portion of the upper surface of the dactylus is 

 granular. 



The upper and lower borders of the walking legs and the upper border of the 

 arms are fringed with hair ; the fringe is replaced on the upper border of the 

 dactylopodites of the walking legs by a close-set covering of short hairs. 



C.I. (rostral lobes included) = 23 '00 ; C.b.-j-C.l. = T33 ; Fronto-orbital b.-i-C.l. 

 = 0'71 ; Antero-lateral border (a straight line uniting the outer angle of orbit 

 with the tip of the 4th antero-lateral tooth) -f- C.I. = '62 ; Postero-lateral border 

 (a straight line uniting the tip of the 4th antero-lateral tooth with the point at 

 which the carapace border meets the 1st abdominal tergum)-j-C.l. = 0'53 ; Posterior 

 border of carapace (line of junction with abdominal tergum l)-i-C.l. = 3'04. 



Remarks. Among forms hitherto described the new species comes nearest to 

 E. mehsfta in general character of the lobules of the carapace and in the absence of 

 the denticle at the outer angle of the orbit. It is somewhat intermediate in the 



