3o8 



Records of the Indian Museum. 



[Vol. XVI, 



I am of the opinion that the resemblances between Mictyris and the 

 Scopimerinae are convergent rather than genetic and I cannot 

 believe that the two have had a common origin distinct from that 

 of the Ocypodinae and Macrophthalminae. 



Apart from the position of Mictyris I differ from Dr. Tesch 

 on a number of points of lesser importance.' With more material 

 before me than was at his disposal I believe that I have been able 

 to discover generic characters of more constant value than those 

 utilised by him on p. 41 of his report. 



In the possession of tympana, curious membranous areas 

 found on the meral segments of the legs and sometimes on the 

 thoracic sterna, the Scopimerinae differ from all other Decapoda ; 

 in some of the genera, however, they are ill-defined and in certain 

 species of Tympanomerus they are altogether absent. The sub- 

 family may be distinguished from the Ocypodinae by the presence 



Text-fig. i. 

 Endopod of second maxilliped. 



a. Scopimera globosa, de Haan. 



b. Tympanomerus gangeticus , sp. nov. 



of a fully formed pleurobranch above the base of the second 

 walking legs and from the Macrophthalminae by the more oblique 

 position and rudimentary' character of the antennules and b}' the 

 greater breadth of the interantennular septum. 



fringed with short hairs. From the sht-like opening thus formed a narrow channel 

 passes forwards on either side to the branchial cavity, 



On placing a Uving specimen of Ge/asiiii/is nciifiis in a bowl of water and 

 introducing a little coloured fluid at the base of the chelipeds I found that the 

 fluid was immediately drawn in and exp(>lled in the ordinary way through the 

 upper part of the buccal cavern. I failed, however, to demonstrate that the 

 accessory openings were similarly used in submerged individuals, even though an 

 attempt was made to inject the' fluid into the pouch, and think it probable that 

 they are emplo}ed only for taking in air. The presence of the fringe of hairs 

 suggests that they are inhalent rather than exhalent. 



' bar instance I regard Dot ilia sigillonim as a species of Scopimera, D. 

 clepsydrodactyliis as a synonym of D. iiitevmedia and Cleistostoma Ungulatitui 

 as a species of Tympanomerus. 



