222 Records of the Indian Museum. [Vol. VI, 



Streptocephalus dichotomus, Baird. 



Chirocephalus stoliczkae,'Woo&M.2iSoi\,^l.^. (^var. simplex, Gur- 



ney). 

 i8g6. BrancJiipus {Streptocephalus) bengalensis, Alcock, Journ. 



.4.5. S.,lxv, p. 538, pl. X. 

 1910. Streptocephalus dichotomus, E. v. Daday, Ann. Set. Nat. 



Zool. (9), xi, p. 349, figs. 63, 64. 



This species is found only in India. It appears to be the com- 

 mon representative of the Anostraca in the plains ; but, in the 

 north-west and south, has been found at considerable elevations. 



The precise locality of Baird's type specimen is unknown; it 

 is stated to have been found alive in a pail of milk. The other 

 records are as follows : — 



1. Near Bangalore, Mysore, ca. 3,000 ft., Oct. 13th, 1910. 



N. Annandale and M. Travers. 



2. Marikuppam, Mysore, ca. 2,500 ft., Oct. 21st, 1910. Mus. 



Collr. 



3. Shevaroy Hills, Madras Pres., ca. 5,000 ft. J. R. Hender- 



son. 



4. Spur Tank, Madras (city), March, 191 1. J. R. Henderson. 



5. Near Calcutta, in flooded rice-fields, 1896, probably June 



or July. {Types oi B. bengalensis, Alcock.) Mus. Collr. 



6. Cutch, Sind. (Types of var. si^nplex, Gurney.) F. Stol- 



iczka. 



7. Dhurampur Kooa, base of Simla Hills, 2,500 — 3,000 ft., 



July 2ist, 1911. Mus. Collr. 



Gurney 's var. simplex ' is distinguishable only in the case of 

 the male : the type specimens from Cutch all belong to this sex. 

 Of twenty-four males from Dhurampur Kooa, ten are typical, 

 while fourteen exhibit the characters of the variety. Forty 

 females were found in the same locality, but it does not seem 

 possible to distinguish two forms among them. 



Although the two forms of male certainly occur together, there 

 is a complete absence of intermediates and, in consequence, the 

 retention of the varietal name appears to be justified. In several 

 male examples the process characteristic of the typical form, near 

 the apex of the upper ramus of the second antennae, is shorter 

 than is shown in the figures given by Sars and von Daday ; but the 

 distinction in this respect between the typical form and the variety 

 is always clear and is correlated with the number of cirriform 

 appendages at the distal end of the proximal antennal segment 

 (four in the typical form : three in the var. simplex). 



A single male from the Shevaroy Hills, one of those deter- 

 mined by Sars, accords with the typical form. But von Dada^^ 

 notes that he received an example of the variety from the Nor- 

 wegian carcinologist and it is probable therefore that both forms 



' Gurney, Journ. A. S. B. (n.s.), ii, 1907, p. 276, pi. v, fig. 11. 



