224 Records of the Indian Museum. [Vol. XVI, 



snout measured from the mouth is just equal to the length of the 

 mouth. The mouth is slightly narrowed forwards. The extent of 

 the labial folds which are poorly developed is nearly the same on 

 the two jaws. The distance of the nostrils from the point of the 

 snout is approximately the same as that from the mouth, and the 

 distance between the two nostrils is much less than the length of 

 the mouth. The eyes are large and prominent, much longer than 

 half the length of the mouth and the distance from the nostril or 

 even the width of the gill-opening. The gill-openings are of the 

 same shape as in the adult. The ventrals, second dorsal and the 

 anal fins are of the same type as in fully grown specimens. The 

 pectorals have their outer margin slightly curved and the posterior 

 nearly straight and not at all showing the characteristic appearance 

 of the fins of the adult. The anals in a male embryo of the size 

 noted have stout elongated claspers not reaching the tip of the 

 fins. The caudal fin is broad in the region of the sub-caudal lobe, 

 where there is a distinct notch ; a second notch is situated 

 posteriorly at a short distance from the tip. 



The placental cord is attached at a point in line with thp 

 anterior edge of the pectoral fins and midway between them 



{fig. I)- 



The colour of the specimens preserved in spirit is slightly 

 greyish with traces of brown on the fins. 



Measurements : — 



Total length . . . . . . io6 mm. 



Snout to caudal pits . . . . 764 mm. 



Snout to fifth gill-opening . . 29*8 mm. 



Snout to mouth . . . lO'b mm. 



I^ength of placental cord . . . . 65 mm. 



Placental cord. — The nomenclature of the parts, the appendi- 

 cula and other points about the external structure are dealt with 

 in the general section at the end of this paper. Here we will, 

 however, describe the internal relations with the foetal organs 

 and the histological structure • 



The placental cord after entering the body of the embryo is 

 seen to consist of an artery and a vein, the outer wall of the cord 

 is not to be seen inside the body. The artery, which is thinner 

 in diameter, passes through the mesentery and, as shown in fig. 2, 

 joins the dorsal aorta. The venous branch, after a short course, 

 opens into the portal vein. 



The placental cord as seen in a transverse section (fig. 7) 

 consists of an artery and a vein surrounded by four main channels, 

 and on the outside surrounded by a wall formed of epithelium two 

 to three cells thick, and having a thin connective tissue lining 

 inside. The wall of the channels mentioned above is also formed 

 of connective tissue. The outer wall of the placental cord is raised 

 into elongated tubular processes, the appendicula ; the structure 

 of these is dealt with further on. 



