

1923.] Fauna of the Chiïka Lake : Fish. 743 



Gobius melanosticta Day, a small Goby from the backwaters of Madras, shows great 

 similarity to the female of the new species. The two can, however, be readily distinguished 

 by the number of their fin-rays, their proportions and colouration. 



The dissection of a male specimen has not revealed the ripe testes. Possibly the two 

 sexes will ultimately have to be regarded as separate species but I have refrained from 

 describing them as such because the number of specimens at present available is very small . 



The following statement gives the number of individuals, their localities and sex : — 



4 specimens ... Off Samal Island ... 22 September 1913 3 $ & 1 <J. 



1 specimen ... Rambha Bay ... 4 September 1919 $ 



1 „ ... OffBarkui ... ... 2 November 1914 2 



Measurements in hundredths of total length without caudal. 



A 



Total length without caudal ... ... ... 21 mm. 25 mm. 



Length of head ... ... ... ... ... 37-1 33-2 



• Depth of head at occiput ... ... ... ... 20-0 20-4 



Breadth of head ... ... ... ... ... 25-7 23-6 



Length of snout ... ... ... ... ... 8-1 8-0 



Diameter of eye ... ... ... ... ... 7-1 7-2 



Interorbital width ... ... ... ... 6-1 6-4 



Depth of body near origin of first dorsal ... ... 19-5 32-0 



Length of caudal peduncle ... ... ... ... 28-5 31-2 



Height of caudal peduncle ... ... ... ... 12-3 14-4 



Length of caudal fin ... ... ... ... 26-6 14-0 



Length of pectoral fin ... ... ... ... 29-5 24-0 



Length of ventral fin ... ... ... ... 28-5 16-0 



Longest ray of dorsal fin. ... ... ... ... 22-3 18-0 



Longest ray of anal fin ... ... ... ... 27-6 20-0 



Genus CTENOGOBIUS Gill. 



The genus Ctenogobius is well represented in the fauna of the Chilka Lake, for there 

 are as many as seven species in the collection. Four are described here for the first time. 

 With the exception of two species, all are very small and may, therefore, have been over- 

 looked elsewhere by collectors. Some of the species which I now assign to this genus have 

 previously been referred to th^ genus Gobius, from which Ctenogobius can be distinguished 

 bv the absence of " silk-like free tips to the upper rays of the pectorals "* and by their 

 smaller size and totally " different physiognomy." 



Ctenogobius acutipinnis (Cuv. & Val.). 

 1876. Gobius acutipinnis, Day, Fish. India I, p. 291, pi. lxi, fig. 2. 

 There are four specimens in the collection, one from Rambha Bay, one from Barkul 

 and the other two from Serua Naddi (September, 1914). The largest specimen is from 

 Rambha Bay and is 41 mm. in length without the caudal. 

 Distribution. — The seas of India. 



1 Jordan and Snyder, Proc. U.S. Nat. Mus.. XXIV, p. 54 (1902). 



