226 Records of the Indiam Museum. [Vor<. XVI, 



dealt with at length by Southwell ' and later by Hussakof.* 

 The embryos were all presented to the Colombo Museum, Ceylon, 

 and we are indebted to the Director of the Museum for kindly 

 sending two of them to us. We are thus able to add a few notes 

 about the internal anatomy and especially the disposition and 

 connections of the yolk-stalk. 



The liver is yellow-ochre in colour and consists of a large 

 undivided right lobe and a much larger left one, which is divided 

 into two. The gall-bladder is small and lies embedded in the left 

 inner lobe of the Hver at its upper end ; the bile duct after 

 receiving the branches from the liver-lobes opens dorsall3^ into the 

 colon close to its commencement. The stomach is large, of a pale 

 yellowish colour and lies on the left side partly covered by the 

 liver; in the specimen dissected it was found to be quite empty. 

 The duodenum is small and of a bluish-green colour. The colon, 

 which is very large and has a well developed spiral valve, lies on 

 the right side. The contents of the colon were found to be a 

 large quantity of partly digested yolk, which is received from 

 the large internal yolk-sac. The internal yolk-sac lies dorsal to 

 the colon and opens into it close to its commencement. The 

 rectum is bent on itself and has a large pear-shaped gland opening 

 into it dorsally. 



The specimen dissected was a female, and had well developed 

 kidneys and oviducts, but only a trace of the ovary was to be seen. 



As has been described above there is a large internal yolk-sac 

 connected with the colon internally. This internal yolk-sac is only 

 an enlargement of the end of the yolk- stalk after it enters the 

 body of the embryo, and forms a sort of reservoir for the yolk 

 from the external yolk-sac before its transference into the colon. 

 Unfortunately the external yolk-sac in both the specimens was cut 

 off and so the relations of the blood vessels of the sac and stalk 

 can not be fully described. At the inner end, where the yolk- 

 stalk enters the body of the embryo, a single artery and a vein 

 were seen. The artery passes dorsally and becomes connected 

 with the dorsal aorta, while the vein enters the hepatic portal 

 vein. The other relations are probably the same as are described 

 further on for RhinohaLis columnae. 



Rhinobatis columnae, Bonaparte. 

 (PI. XVIII, figs. 1-6.) 



1832-41. Rh. coliininae, Bonaparte, Fauna Ifalica, Pesci, No. 152, plate. 

 1909. Rh. coluvinac, Annandale, op. cit., pp. 14-15. 



Annandale in the paper cited above has discussed the name, 

 etc., of the Indian species. We have before us two stages of very 

 different ages, — one of a shark-like form and the second in which 

 the embryos resemble the adult in general shape, though still 



1 Spolia Zeylanica, VI, pp. 137-139, i pi. (1910). 



2 Bull. Amer. Miis. Nat. Hist,, XXXI, pp. 327-330, fi.s^s. i, 2 (191 2). 



