DEVELOPMENT. 



2 7 



It is observed that after the eggs are deposited the oviducal openings are everted, 

 tumid, suffused with blood (plate i, fig. 2; cf. also Costa, p. 23, plate n, andGaimard, 

 plate xx, in Voy. en Islande et au Greenland); in fact, the entire anal region is 

 bloodshot, including the fin margins. 



In many instances (August and September) the fish may soon spawn again. 

 1 his is evident from the mature condition of a pair of ovarian eggs which were 

 found in specimens having tumid oviducal openings. 



RATE OF EMBRYONIC DEVELOPMENT. 



The young Chimaera spends the greater part of a year in its capsule, probably 

 not less than nine months, and possibly as long as twelve. The duration of the 

 younger stages is known with reasonable accuracy. In the following table, show- 

 ing the rate of development of C. colliei, the results are based upon eggs in hatch- 

 ing-cases (water temperature between 50 and 60 F.). 



TABLE B. Kate of Embryonic Development. 



Stage. 



Fertilization. 

 Cleavage. . 



First . . . 



Second . 



Sixth. . . 



Blastula 



Gastrula .. 



Embryo. 



Estimated 



duration of 



entire process. 



36 to Go hours 

 3 days. 



4 days . 

 14 days . 



Approximate age of specimen in material studied, time of 

 fertilization included.* 



2 days 3 hours. 



2 days 5 hours. 



3 days. 



5 to 9 days. 



10 days. 



12 days, corresponding to Balfour's shark embryo stage C. 



19 days, corresponding to Balfour's shark embryo stage D. 



21 days, corresponding to Balfour's shark embryo stage E. 



24 days, corresponding to Balfour's shark embryo stage F. 



28 days, corresponding to Balfour's shark embryo stage G. 



33 days, corresponding to Balfour's shark embryo stage I. 



90 days, f corresponding to Balfour's shark embryo stage L. 

 130 days, f corresponding to Balfour's shark embryo stage N . 

 180 days, \ corresponding to Balfour's shark embryo stage O. 



*A re-examination of the writer's collecting notes leads him to estimate that fertilization takes place 

 in about two days. This time has therefore been added in assigning ages to the various stages. 



tThese figures are based upon notes given by the fisherman Ah Tack, recording months when eggs were 

 placed in the hatching-cases. If these are accurate, and I believe they are reasonably so, Cliiiniera does not 

 differ notably from a shark in its rate of later embryonic growth. 



THE EGG. 



The egg of C. colliei measures in its capsule about 2.9 by 1.9 by 1.3 cm. 

 (average). It is inclosed in a delicate vitellina ; when this is ruptured, the egg breaks 

 into a syrupy mass, very much as the egg of a typical selachian. Especially 

 soft is the egg about the time of its passage into the oviduct. At such a stage 



