762 Memoirs of the Indian Museum. [Vol. V, 



Family PLATYCEPHALIDAE. 



Genus PLATYCEPHALUS Bl. & Sehn. 



Platycephalus insidiator (Forskâl). 

 1876. Platycephalus insidiator, Day, Fish. India, I, p. 276. 



A few specimens of this species were taken in the outer channel, to which it is evidently 

 an occasional visitor. 



Disribution. — The Red Sea, east coast of Africa, the seas of India, the Malay Archi- 

 pelago and beyond. 



Sub-order OPISTHOMI. 

 Family MASTACEMBELIDAE. 

 Genus MASTACEMBELUS Cuv. and Val. 

 Mastacembelus armatus (Lacépède). 



1878. Mastacembelus armatus, Day, Fish. India, II, p. 340, pi. lxxiii, fig. 2. 



The species is represented by two specimens captured near Patsahanipur. The largest 

 is about a foot a n d half in length. 



The fish is probably an occasional immigrant from fresh waters in the rainy season. 



Distribution. — The fish occurs in the fresh and brackish waters of India, Ceylon and 

 Burma. Its range extends as far as China. 



SUMMARY OF THE REPORT ON THE FISH OF THE CHILKA LAKE. 



The fish-fauna of the Chilka Lake comprises in all 118 species, of which 13 have been 

 found to be new. Most of the new species, as many as seven, belong to the family Gobiidae, 

 while the remaining six are distributed among the families Clupeidae, Siluridae, Ophich- 

 thyidae and Sphyraenidae. A new genus, Micrapocryptes, has been erected in the family 

 Gobiidse to accommodate the small transparent Gobies of the lake and the Gangetic 

 Delta. In the genus Eleotris a specimen is recorded without any specific name. It probably 

 represents a species hithereto undescribed but I have refrained from naming it on account 

 of the immaturity of the single specimen. 



Of the 118 species, 49 were taken in the main area only, 24 in the outer channel only 

 and 39 from all over the lake. The distribution of the remaining six species in the lake is 

 not known because they appear to have been purchased from local fishermen from time 

 to time. 



The most noteworthy feature in the physical environment of the fauna of the lake is 

 the great periodic change in salinity. This has been fully discussed in the introduction to 

 this volume by Annandale and Kemp (pp. 6 — 10) and also by Sewell in his paper on 

 Rambha Bay (pp. 680-690). Most of the fishes inhabiting the lake are known from the 

 estuarine waters of India and bhe Malay Archipelago, but certain forms such as Pseudo- 

 rhombus arsius, Gerres punctatus, G. öyena and Gobius albopunctatus, which have hitherto 



