1920.] B. Prashad : A new species of Thalassema. 37 



The living specimens were of a pale pinkish colour due largely 

 to the pinkish coelomic fluid which could be seen shining through. 

 The proboscis and the two ends of the body were light yellow with 

 a tinge of green here and there. Specimens preserved in spirit 

 after fixation in 10% Formalin are of a deep yellowish colour. 



The two type-specimens, since the description was written, 

 have unfortunately been lost and are not available for future 

 reference. I have, however, requested Mr. R. H. Whitehouse, 

 Marine Biologist of the Madras Fisheries, to kindly procure some 

 more specimens from the original locality. 



Relationships : — The species described in the previous pages 

 differs from the other known species of the genus in having five 

 pairs of segmental organs and the musculature divided into nine- 

 teen bundles. It shows a distinct advance on the condition des- 

 cribed by me in T. kempi ' in having five pairs of segmental 

 organs, even though the number of muscle-bands has become 

 reduced to nineteen. 



Remarks : — As has been noted above, the animals showed 

 great powers of extension and contraction of the body. One 

 of the specimens also showed the phenomenon of the autotomy of 

 the proboscis, as it threw off the proboscis on being taken out of 

 sea water. This latter peculiarity has been observed in the case 

 of other marine species, but the group of the essentially brackish 

 water Asiatic species {loc. cit.) of the genus differs very markedly 

 in this respect from the marine species, 



1 Mem. As. Soc. Bengal, VI, pp. 321-33S, pi. xi (igig). 



