244 Records of the Indian Museum. [Voi,, IX, 



were also obtained in the northern part of the Andaman Sea in 

 1897-98. The shape of the test of the solitary form has been 

 noted by W. K. Brooks ("The Genus Salpa": Mem. Biol Lab. 

 John Hopkins Univ.) but the dorso-lateral keel does not seem to be 

 prolonged posteriorly to the same extent as he indicates. 



The firm part of the test ends abruptly posteriorly and is here 

 of a triangular sectional form, the angles being formed by the two 

 dorso-lateral and the mid-ventral keel. On either side there are 

 on the test two other ridges, one above the dorso-lateral keel, and 

 one between the dorso-lateral and the ventral keel. These ridges 

 terminate posteriorly a little in front of the posterior termination 

 of the firm part of the test. 



In the aggregate generation, the ventral ends of muscle X, on 

 the under side of the atrial aperture, cotne into contict one with 

 another and then, diverging, pass forwards a short distance in the 

 ventral wall of the atrial siphon. 



4. Salpa hexagona, O. and G. 



One very fine example of the solitary generation was obtained 

 in a mid-water net at station 39^ (7 2r'6" N., 85°7'i5" E.) This 

 measures y^ mm. from branchial to atrial apertures, the posterior 

 processes of the test 'adding another 13 mm. to the length. 



No specimens of the aggregate generation have been met with. 



5. Salpa confoederata, Forskal. 



Numerous specimens, both of the solitary and the aggregate 

 generations, were obtained near Preparis North Channel (I5°25' N., 

 93°45' E.) on i6th November, 1909. 



6. Salpa multitentaculata, Q. and G. 



A few of the aggregate generation were obtained in a mid- 

 water net at station 461 (io°i5' N., 90°i5' E.) on 19th April, 

 1912, Except for their contained embryos none of the solitary 

 generation have been found. 



7. Salpa deniocratica, Forskal. 



These have been found in the northern part of the Andaman 

 Sea and at numerous stations among the Islands of the Mergui 

 Archipelago. The individuals are much smaller than some speci- 

 mens from Plymouth, England, that are in the Indian Museum, 

 the largest specimen of the solitary form that I have measured 

 being only 11 mm. long. The posterior processes of the test are 

 also relatively shorter than in those from EngHsh waters. During 

 the last survey season, spent in the Mergui Archipelago, the only 

 species I obtained were S. democratica and 5. cylindvica. These 

 generally occurred together, but opposite the town of Mergui, in 

 the Tenasserim R., only the former was obtained. 



