84 PEOCEEDINGS OF THE NATIONAL MUSEUM. vol. 64, 



Carcharhinus commersonii. 



1923, August 4 : Record is here made of three small cestodes with 

 red pigment spots in the neck, and in other recognizable features 

 agreeing with R. tenuispine, but with slightly coarser hooks. 



(U.S.N.M., Helm. Coll. 7712.) 



Larval stage. 



Sconiber scombinis. 



1905, August 18: Cysts in stomach wall, associated with cysts of 

 R. longispine, scoleces with minute, and moderately regular hooks, 

 3 fish examined. 



RHYNCHOBOTHRIUM WAGENERI Linton. 



1890, pp. 843-S45, pi. 12, figs. 10-12. 

 1901, p. 433. 

 1911, p. 588. 



Dasf/hatis centrura. 



1911, September 14: 75. This is the only record I have of this 

 species since it was first described. Measurements of specimens from 

 this lot were in agreement with those given in the original descrip- 

 tion. The most characteristic feature of this species is the single^, 

 relatively large hook at the base of each proboscis; all the other 

 hooks being very small, and not differing greatly either in size or 

 shape. The following measurements are from a specimen mounted 

 in balsam: Diameter of proboscis, exclusive of hooks, 0.066, includ- 

 ing hooks 0.075; length of a small hook 0.015, breadth at base 0.004: 

 length of the solitary large hook at the base of a proboscis 0.045; 

 breadth at base 0.024. 



(U.S.N.M., Helm. Coll. 7713.) 



RHYNCHOBOTHRIUM, species. 



Plate 7, figs. 71-73. 



Record is here made of scoleces from the torpedo, 1 from cyst on 

 spiral valve, 4 scoleces, probably liberated from cysts which had 

 been recently introduced with food. 



Narcacio7i nohilianus. 



1911, July 21 : 4 scoleces, all small. The mounted specimens are 

 from 1.64 to 2.24 mm. in length, from anterior end to base of con- 

 tractile bulbs; length behind the bulbs varies from 0.28 to 0.56 mm. 



Dimensions of specimen showing front view of bothrium; length 

 to base of bulbs, 2.22, behind bulbs, 0.56; bothrium, length 0.42, 

 breadth 0.56; diameter at bulbs 0.49; bulbs, length from 0.45 to 

 0.52, diameter 0.08. 



Dimensions of specimen showing lateral view of bothria : Length 

 to base of bulbs, 1.75, length behind bulbs 0.56; length of bothrium 

 0.38; diameter of scolex through bothria 0.56, at bulbs 0.34; bulbs, 



