The Embryology of Chlamydoselachus 



527 



would have supplied details not recorded among the very few notes available. 



In this difficult task, I have been fortunate in having the active help and cooperation 

 of Dr. B. G. Smith. It is a pleasure to acknowledge my large obligation to him. 



THE SPECIMENS AND THEIR SOURCE 



That the collecting of eggs and embryos of Chlamydoselachus was not the main 

 object of Dean's first visit to Japan, and that the finding of these eggs was somewhat un- 

 expected, it attested by this statement (Dean, 1901.1) — ''My first object in visiting Japan 

 [in 1900] was to secure the eggs and embryos of the Port Jackson shark [Heterodontus = 

 Cestracion].''' The eggs oi Heterodontus were found among rocks and seaweed in shallow 

 water, and were easily collected by divers and maintained without difficulty in aquaria of 

 running water or in floats in the sea. Hence it is not surprising that Dean procured 

 a fairly complete series of early stages of the embryos of this shark and that he devoted 

 most of his time to their study. The drawings of the eggs and embryos of Heterodontus, 

 which are more numerous than those of Chlamydoselachus, will form the basis of the final 

 article in this Memorial Volume. 



Text-figure 1 

 A map of the Sagami Sea, the Miura Peninsula, and part of the Gulf of Tokyo, showing the position of 

 the Misaki Laboratory in which Doctor Dean worked, and the waters from which his specimens of 



Chlamydoselachus were obtained. 

 From an old chart compiled by Prof. I. Ijama. 



