1923.] 



Fauna of the Chilka Lake : Fish. 



753 



the minute set of teeth, there are developed in both jaws a number of comparatively 

 large conical teeth, which are distinctly visible to the naked eye. In the upper jaw there 

 are about nine teeth on each side and they diminish in size as they recede from the middle 

 of the jaw towards the angle of the mouth. In the !ower jaw the big teeth are developed 

 only in the middle and there are usually four of these of almost equal length on each side. 

 The big teeth in both the jaws are separated from each other. Near the angles of the 

 mouth on each side in the lower jaw are a number of minute, closely set teeth. These 

 probably represent the dentition of the young individual. The canines become very con- 

 spicuous and are curved near their extremities. 



In the development and structure of the teeth the Indian transparent Goby runs 

 almost the same course as has been described by Collett 1 for the two European transparent 

 Gobies (Aphia pellucidus and Crystallogobius nilssoni). I have not, however, been able to 

 determine in this new form all those points which have been so ably discussed by Collett for 

 the European genera. 



The first dorsal fin consists of five weak spines none of which is longer than the diameter 

 of the eye. The second dorsal consists of a spine and 

 from seven to eight branched rays. The second branched 

 ray is the longest and its height is greater than the depth 

 of the body. The spine is as high as the length of the 

 base of the second dorsal. The anal consists of one spine 

 and from ten to eleven branched rays ; the second 

 branched ray is the longest and is equal in length to the 

 depth of the body immediately below the first branched 

 ray of the second dorsal. The pectoral is as long as the 

 longest ray in the second dorsal ; it usually contains 

 thirteen to fourteen rays and its posterior extremity is 

 rounded. The pelvic is situated on a raised area and 

 begins immediately below the base of the pectoral. The 

 fins are united for a considerable length and form a 

 regular funnel-shaped tube. The caudal is truncate and 

 consists of thirteen rays besides a number of smaller rays 

 on the sides. 



The scales are of moderate size ; but they are ex- 

 tremely thin and are hardly distinguishable with the 

 naked eye. There are 27 between the angle of the 

 operculum and the base of the caudal fin. There are 

 seven in an oblique line between the anterior origin of 

 the anal fin and the base of the second dorsal. The scales 

 are firmly set together. Under the microscope a series 

 of small spines is seen along the posterior border of every scale, but I have not been 

 able to make out any definite striae in the central portion. In a microscopic prepara- 



». 



a. 



Text-fig. 33. — Under surface of male and 

 female of Micrapocryptes fragilis, gen. 

 et sp. nov. 



a. Male : x 5£. b. Female : x 4. 



1 Collett, Proc. Zool. Soc. London, -pp. 318—339 (1878). 



g2 



