538 Memoirs of the Indian Museum. [Voi,. V, 



namely three large ones at the apex and three minute ones on the inner margin of 

 each lobe. 



Chevreux has recently (1913, p. 15) recorded the occurrence of Quadrivisio 

 bengalensis in the island of Zanzibar; his specimens are found in a cave and have 

 the eyes imperfect. He does not state whether there are any differences between 

 his specimens and the description given by Stebbing. 



Dr. Annandale has sent me specimens from four localities in the Talé Sap, Siam, 

 which appear to be quite the same as the Chilka L,ake specimens. 



The peculiar character of the eye by which it is divided on each side into two 

 separate pigmented portions is best marked in adult specimens. In one small 

 specimen, 2 mm. in length, the eye on each side is single, being somewhat irregularly 

 rounded and situated in the usual position slightly below the base of the upper 

 antenna; in another specimen, slightly larger, the main portion of the eye corres- 

 ponds with that in the first specimen, but it is continued upwards towards the 

 dorsal surface of the head as a narrow pigmented projection. In older specimens 

 this portion becomes enlarged, at first remaining connected with the older part of 

 the original eye but later on becoming quite distinct. The appearance of the eyes 

 in adults as seen from above is well shown by Stebbing (1907, pi. VII oc). 



[Common under stones just below water-level all round the lake. Also seen 

 swimming in pairs at the edge. N.A.] 



Orchestia platensis Kröyer. 



(Text-fig. 7). 



Orchestia platensis Kröyer, 1845, Naturh. Tidskr ser. 2, v.l. p. 304, pi. 2. f. 2. 



Orchestia platensis Stebbing, 1906, p. 540. 



Orchestia platensis Stubbing. 1900, p. 527, pi. 21a. 



Orchestia platensis Chevreux, 1908, p. 494, fig. 14. 



Orchestia agilis Kunkel, 1918, p. 118, fig. 31. 



Orchestia pickeringii Dana, 1852, p. 882, pi. 59, fig. 9. 



Orchestia pickeringii Stebbing, 1900, p. 528. 



Orchestia pickeringii »Stebbing, 1906, p. 538. 



Localities : — 



Barkul. Several specimens, males and females. 

 Chirriya Island. Several. 



After much consideration I am referring these specimens to Orchestia platensis 

 Kröyer, a species which according to Stebbing has a very wide distribution. 

 Kröyer' s original specimens were from the Rio de la Plata, north-west of Monte 

 Video, and Stebbing records the species from the Atlantic Coast of North America 

 (where it has long been known as Orchestia agilis S. I. Smith), the Bermudas, the 

 Mediterranean, Lake Tiberias and also from the Hawaiian Islands where it was 

 obtained at two localities at heights of 3,000 and 2,000 ft. respectively. 



I had first identified the Chilka I y ake specimens with 0. pickeringii Dana which 

 had been recorded from Hawaiian Islands, California and from New South Wales. 



