2i8 Records of the Indian Museum. [Vol. XVI, 



which elapse before this is absorbed, the fry lie quiet and idle, and 

 do not swim unless disturbed. 



The following stages were present in the collection : — 



(i) Stages with the embryos still enclosed in large 



globular eggs (figs. 4-6). 

 (ii) Embryos hatching out, some having the egg 



membrane still attached, 

 (iii) Stages with the embryos having the yolk-sac in 

 various stages of absorption (figs. 7-10). 



The following descriptions are based on whole mounts or dis- 

 sections only, as the specimens were found to be too poorly pre- 

 served for section cutting : — 



The eggs are of a yellow colour owing to the contained 

 yolk being of this colour in preserved specimens. Nothing is 

 known regarding the colour of this mass in the living eggs. The 

 eggs are large, measuring about 5*2 mm. in diameter. The egg- 

 membrane, on the surface of attachment, is raised up into small 

 projections ( fig. 4 ) by means of which the eggs are attached 

 to stones or other objects in the nest. Some clusters of from 

 three to five eggs were also found adhering to one another by 

 their sides, and these also showed similar surface projections. 



On the following page we have given in a tabular form the 

 sizes of five of the later stages and other details of measurement 

 of various organs, etc., in the respective stages. Other details will 

 be found in the detailed description. 



Stage I (fig. 4). — This stage is a fairly advanced one, the 

 contained embryo having already grown to 7*1 mm. in length. 

 The embryo lies within the egg-membrane in a slightly coiled posi- 

 tion over the yolk-sac, and shows a continuous fin- fold along 

 the dorsal and ventral surfaces and over the tail, the division 

 into the various portions not being marked oft* at this stage. The 

 head is differentiated but still attached to the yolk-sac ventrally. 

 The eye and the ear are formed, but the pigment has not been 

 deposited as yet in the eye. Lying posterior to and below 

 the eyes is the heart, its demarcation into chambers has already 

 comirienced but has not advanced sufficiently for the various divi- 

 sions to be identified. The notochord has a straight course in the tail , 

 and is not turned upwards. The mouth opening is seen as a 

 slit and the rudiments of the branchial arches are also present. 

 The tube of the alimentary canal and the liver mass are just distin- 

 guishable. The air bladder is present as a small, slightly oval sac. 

 In the bod}^ and in the tail region the myocommas of a < shape 

 are present ; fifty-seven were counted in a specimen but in the 

 terminal portion of the tail their boundaries could not be seen. 



Stage II (figs. 5-6). — This stage is only a little more advanced 

 than the previous' one, and but for the lobes of the brain being 

 better marked, the myocommas better developed, the myosepta 

 having a more wavy outline and the eye and the air-bladder being 

 more distinct, there is nothing special to mark in this stage. 



