30 Records of the Indian Museum. [Vol. VII, 



specimen, the only known example of its sex, differs from the 

 males in the following features : — 



1. The spine on the carapace at the posterior end of the 

 intestinal region is blunt — little more than a tubercle — 

 and cannot be said to overhang the posterior margin. 



2. The lamelliform teeth which fringe the lateral and posterior 

 margins of the carapace are much less conspicuous. 



3. The 4th — 6th abdominal terga are fused and the sutures 

 partially obliterated ; but the telson is freely movable. All 

 the segments are covered with vesiculous granules and at 

 the distal end of the sixth there is a blunt tubercle com- 

 parable with that found in the male but by no means so 

 evident. 



4. The coxal joints of all the legs are elevated on either 

 side of the abdomen and form a thin outstanding crest. 



The close-set tubercles which cover both surfaces of the cheli- 

 peds and the upper portions of the merus, carpus and propodus 

 of the ambulatory legs are in both sexes much more conspicuous 

 than is shown in plate v of the '' Investigator " Illustrations. 



Tribe Brachygnatha. 



Family GON OP LAC I DAE. 



Sub-family CARCINOPLACINAK. 



Psopheticus stridulans, Wood-Mason. 



Psopheticus stridulans, Alcock, 1899, p. 73 ; 1900, p. 309, and ///. 



Zool. Invest., Crust., pi. v, fig. i. 



One specimen, a female with carapace 11 mm. in length, was 

 found at St. 391. P. stridulans has, hitherto, only been recorded 

 from the Andaman Sea and S. W. of the Great Nicobar. 



Family MAIIDAE. 



Sub-family INACHINAB. 



Physachacus ctcnurus, Alcock. 



Physachaeus ctenurus, Alcock, 1899, p. 40; III. Zool. Invest., 

 Crust., pi. xviii, figs, i — ib, and Doflein, 1904, p. 71, pi. xxiv, 

 figs. I — 4, pi. xlii, figs. I — 7, pi. xlviii. 

 Two males and one ovigerous female were obtained at St. 391. 



Sub-family PISINAE. 



Sphenocarcinus aurorac, Alcock. 



Splienocarcinus aurorae, Alcock, 1899, p. 84. 



Twelve males and fifteen females (ten ovigerous) were 

 obtained at St. 391. A drawing of this species, which has not 

 hitherto been figured, will be found on pi. i, fig. 10. 



