122 BULLETIN OF THE BUREAU OF FISHERIES. 



HABITATS OF THE PARASITE. 



The following list of hosts in which this species has been found is a compilation 

 of both oublished and unpublished notes of my collections made at Woods Hole, 

 Mass., iesufort, N. C, Tortugas, Fla., and in Bermuda. 



ADULT STAGE. 



In spiral valve of the following hosts: 



CarcharMnus obscurus (?). Dusky Shark. 

 Beaufort, N. C: 



1902— Aug. 26, few. 



CarcharMnus platyodon. 

 Tortugas, Fla.: 



1906. — July 12, two small specimens. 



Scoliodon terrx-novx. Sharp-nosed Shark. 

 Beaufort, N.C.: 



1901. — July 16, one, length 10 mm. ; free segments, length 3 mm. 

 July 18, two. 



July 22, six, length 1 to 7 mm.; posterior segments easily detached. 

 July 22, three. 

 August 15, one. 

 1902. — July 11, twenty-nine from one shark; also numerous cysts with scoleces 



in stomach wall. 

 This shark was examined on 18 other occasions when this parasite was not found. 

 All the sharks of this species which were examined were, with one exception, small, 

 25 to 30 cm. ; one measured about 100 cm. 



Splvyrna zygxna. Hammerhead. 

 Woods Hole, Mass.: 



1886.— July 28, one hundred and fifty. 

 18S7.— July IS, one hundred. 



Chyle swarming with free proglottides in each case. 

 1898.— July 21, three.' 



A small hammerhead was examined on August 5, 189S, another on August 18, 

 and another on July 31, 1899. Otobotlmum crevacolle not found on either date. 



ENCYSTED STAGE. 



Balistes carolinensis. "Turbot." 

 Bermuda: 



1903. — July 14, a few small cysts in walls of stomach and intestines. 



July 22, a few cysts in intestinal wall. 

 The closely related species Balistes vetula was examined also. There were 

 numerous cysts in the intestinal wall, but all that were opened contained only 

 chalky, degenerate tissue, with no trace of parasite. 



