CALIFORNIA FISH AND GAME, a8} 
THE GROWTH OF THE SWELL SHARK WITHIN 
THE EGG CASE.* 
By Heten M. Epwarps. 
On March 17, 1920, a young shark in the egg cage was received from 
Mr. Kiati Nasu, secretary of the Southern California Fishermen’s 
Association, through the kindness of Mr. E. M. Nielsen, of the Fish 
and Game Commission at San Pedro, and of Mr. Lingle, of the 
Bureau of Fisheries, who 
brought it to Hopkins Marine 
Station, Pacifie Grove. The 
development of the fish has 
been watched with much in- 
terest, because the species was 
unknown and the process of 
development had not been 
seen in any of our western 
sharks. 
Upon receipt of the shark it 
was placed in a small salt 
water aquarium with running 
water, where it was kept 
during its development. At 
various times the aquarium 
was out of order, which made 
it necessary at such times to 
change the water on the fish 
two or three times a day or to 
move it into another aqua- 
rium. It is a question whether 
or not the process of develop- 
ment was retarded or hin- 
dered in any way by these 
disturbances. We are under 
{obligation to Stanford Uni- 
ij versity and to Dr. W.: K. 
Fisher, the director of Hop- 
kins Marine Station, for the 
use of the aquarium. 
The case, as shown in the 
accompanying drawing, was 
116 mm. long and 49 mm. 
wide. One end, comprising 
about one third ‘of the length 
of the case, was considerably 
smaller, and of a different 
shape from the larger end. 
The acute angles of the latter 
met and continued in long 
slender tendrils, for the pur- 
pose of attaching to seaweed, 
while similar tendrils were 
Fic. 39. Egg case of Swell Shark Catulus 4 
uter. Natural size. also given off from the angles 
*California State Fisheries Laboratory, Contribution No. 20. 
