420 CEYLON PEART- OYSTER REPORT. 



Thalamita adraeta (Herbst, 1803) A.4, p. 83. 



Localities : Pearl banks, Gulf of Manaar, 58 specimens ; coral reefs. Gulf of Manaar, 

 four specimens ; off Negombo, one specimen ; off Mutwal Island, four specimens ; 

 Muttuvaratu Paar, two specimens. 



All the above specimens come under var. admeta as defined by Borradaile 

 (p. 202). The fourth tooth of the anterolateral border of the carapace, considerably 

 reduced in all, is very rudimentary in some particularly among the females. It is, 

 perhaps, most rudimentary, however, in one of the adult males. 



Thalamita exetastica, Alcock, 1899 A.4, p. 86 ; A, Invest., pi. xlvii., figs. 2, 2a. 



Localities : Pearl banks, Gulf of Manaar, two specimens (adult ? , one ovigerous) ; 

 south of Galle, deep water, one specimen (adult V ). 



Description: As in Borradaile's specimens (p. 203), the squamiform markings 

 of the cheliped are almost absent ; a trace only is present, on the upper distal portion 

 of the arm. On the upper surface of the arm and on the upper portion of the outer 

 surface there are more or less rounded granules ; the inner surface, the under surface, 

 and the lower portion of the outer surface are smooth. The ridges of the carapace 

 are well marked. 



In the ovigerous female there are one or two spinules on the posterior border of 

 the propodite of walking leg 4. This is an approach to Charybdis orientalis, Dana. 



Thalamita integra, Dana, 1852 -A.4, p. 85. 

 Locality : Pearl banks, Gulf of Manaar, six specimens. 



Thalamita investigatoris, Alcock, 1899 A.4, p. 85 ; A. Invest., pi. xlvii., fig. 1. 



Localities : Off Mutwal Island, one specimen ; Gulf of Manaar, deep water, three 

 specimens ; deep water off Galle, four specimens ; coral reefs, Gulf of Manaar, one 

 specimen (a). 



Description : There are five ovigerous females, one young female, one adult male, 

 and two young males. CI. of an ovigerous female = 7 "00. 



Spines are present on the propodite of walking leg 4 as described by Alcock, but 

 omitted from his figure. As differences from Alcock's description of the single male 

 for which he creates the species one notes that the median lobes of the front tend to 

 have a straight rather than a rounded anterior border, and are not obviously more 

 prominent than the sub-median pair, the latter point agreeing with Alcock's figure, 

 however. I should not describe the fifth tooth of the antero-lateral margin of the 

 carapace as " very" small. The wrist and hand bear more numerous spines. 



The fourth tooth of the antero-lateral margin of the carapace is absent in one of 

 the ovigerous females (). 



Thalamita sexlobata, Miers, 1886 A.4, p. 87. 

 Localities: Pearl banks, Gulf of Manaar, eight specimens; coral reefs, Gulf of 

 Manaar, four specimens ; off Mutwal Island, one specimen. 



