80 PROCEEDINGS OF THE NATIONAL. MUSEUM. vol.64. 



RHYNCHOBOTHRIUM TUMIDULUM Linton. 



1890, pp. 829-832, pi. 11, figs. 3-1]. 

 1897a, p. 448. 



1900, p. 270. 



1901, pp. 425, 431, 468. 

 1905, pp. 348, 409. 

 1911, p. 588. 



Adult stage. 



C archarhinus obscurus. 



1907, July 31 : 2, in spiral valve. 



Galeorhinus laevis. 



Collected in 4 of the years from 1903 to 1907 : On 2 dates in July, 

 1 on one date, 30 on tlie other; on 6 dates in August, 6 to numerous, 

 with ripe segments which were brown almost black ; ova conical, with 

 bristles; on 2 dates in September, 3, with ripe segments, in 1 of 15 

 dogfish, on one date, and 28 in one dogfish, and 26 in another on the 

 other date. 



(U.S.N.M., Helm. Coll. 7709.) 



Larval stage. 



Lophius piscatorius. * 



1903, October 29: 1, scolex attached to plerocercus. Dimensions, 

 life: Length of larva, 5; maximum diameter, 1; diameter at bulbs, 

 0.63 ; length of bulbs, 0.27 ; hooks not satisfactorily shown, but largest 

 about 0.03 in length. In balsam the length of the scolex to base of 

 bulbs is 0.67; breadth at base, 0.56; behind bothria, 0.35; bothria, 

 length, 0.33; breadth, 0.40; length of bulbs, 0.21; proboscides re- 

 tracted and hooks not clearly shown; length, about 0.021. 



Opsanus tau. 



1910, October 5: 1 cyst, 4 by 1.5 mm.; proboscides of scolex re- 

 tracted; referred provisionally to this species. Dimensions of a 

 scolex mounted in balsam of date already reported (1901, p. 468) : 

 Length, much contracted, 0.98, breadth at base of bulbs 0.77, at an- 

 terior end behind bothria 0.35 ; length of bothrium 0.22, breadth 0.26 ; 

 length of bulbs 0.35, breadth 0.08; diameter of proboscis, excluding 

 hooks, 0.024; hooks slender, and, so far as seen, arcuate, maximum 

 length about 0.009. 



Spheroides maculatus. 



1907, August 10: 2 scoleces attached to plerocerci, in intestine, red 

 pigment in neck. Dimensions in balsam : Length of scolex, 0.70, 

 breadth at base, 0.53, at anterior end 0,25 ; length of bothrium 0.22, 

 breadth 0.21; length of bulbs 0.28; plerocercus, length 1.26, a little 

 broader than scolex at anterior end, tapering to 0.21 at posterior end ; 

 hooks very small. 



