300 Bashford Dean hiemorial Volume 



amount of ingested food, or to the presence of eggs in the uterus. Of the two conjec- 

 tures we prefer the latter. 



Nishikawa's drawings (his figures 1 and 2) show that the egg of Chlamydoselachus 

 has an egg-case produced at one end into a long tapering curved process or hook, and at 

 the other end into a smaller mound-like excrescence. One of the hooks is plainly shown in 

 Text-figure 24. Such an egg-case is to be expected in this primitive form. But one would 

 not expect viviparity in a shark with so many primitive characters, since oviparity seems 

 to have been the primitive method of reproduction among the sharks. Dean himself 

 recognized this fact, for he says in his one communication (1903) on Chlamydoselachus, 

 after commenting on the huge size of the eggs, that it is a very archaic type. He adds: 



"that it was, however, until recently an egg-de- 

 positing shark is apparent from the character of 

 the horn-like capsule (with rudimentary tendrili- 

 form processes) which the egg still retains." 



With Dean's visits to Japan in 1900-1901, 



and 1905, the knowledge that Chlamydoselachus 



is viviparous became widespread. Elsewhere it 



is noted that Dean records the capture of 39 



Text-figure 24 specimens. We know that 12 of these were 



Egg-shell, egg, and embryo of Ch/amjidoselochus males, and 27 were females. Dean's fragmentary 



shown in one-half natural size. ^otes show that 11 females carried 53 eggs in the 



After Nishikawa, 1898. "uteo." Also, wc leam from his notes that 



other embryonic material was collected and shipped to him. Suffice it to say that 



Nishikawa's article (1898) and Dean's first visit to Japan shortly thereafter (1900) settled 



forever the question of viviparous reproduction in the Japanese frilled shark. 



The young are born alive, are evidently of large size at the time of parturition, and 

 when they emerge from the cloaca of the mother they are able to forage for themselves. 

 Rose's not-yet-extruded young specimen was 340 mm. (13.4 in.) long. The largest of our 

 six embryos are 320 mm. (12.6 in.) long and 374 mm. (14.7 in.) over all. These are uterine 

 embryos, for though the yolk-sac has been removed from the first, attached to the second 

 (the largest embryo that we have examined) is a huge yolk-sac 80 mm. (3.1 in.) in its 

 longest diameter after being in preserving fluid about 30 years. How large the young are 

 at birth can only be conjectured — we would hazard the guess that they are at least 600 

 mm. (24 in.) long. When one realizes that there may be as many as 12 embryos in one 

 uterus, one can visualize the tremendous distention of the body of this slender shark during 

 gestation. One can then understand better the huge abdomens of Bertrand's and Ito's 

 fish (our Figure 5, plate I; and Text-figure 5). 



In the above paragraphs we have brought together all the data known to us bearing 

 on the subject of the breeding habits. Dean's notes on our fish are very fragmentary. 

 In the notebook labelled Chlamydoselachus, we find pages having headings for what 

 was intended to be a natural history of the fish, but nearly all are blank, as for instance 



