[39] ENTOZOA OF MARINE FISHES OF NEW ENGLAND. 491 



convex. In others they could not all be made out definitely, but enough 

 could be made out to show that they were irregularly placed. 



Habitat. — Common Eel ( Anguilla vulgaris) ; intestine; 12 specimens, 

 S and 2; September 2, 1885. Dusky Shark (Carcharias obscurus); 1 

 specimen, S ; August, 1884." Wood's Holl, Mass, 



Of the following specimens of which measurements were made, No. 

 1 is a female, Nos. 2 and 3 are males. No. 3 is the specimen obtained 

 from the spiral intestine of C. obscurus : 



Dimensions. 



Length of specimen 



Length of proboscis 



Breadth of proboscis, apex 



Breadth of proboscis, base 



Length of proboscis sheath 



Breadth of proboscis sheath . . . 



Length of lemnisci 



Breadth of body, anterior 



Breadth of body, greatest 



Breadth of body, posterior end. 



No. 1, $ 



mm. 

 9.50 

 0.17 

 0.17 

 0.15 

 0.46 



1.50 



No. 2, d 



mm. 

 6.44 

 0.105 

 0.14 

 0.12 



No. 3, d 



mm. 

 4.60 

 0.16 

 0.162 

 0.132 

 0.30 

 0.12 

 1.40 

 0.19 

 0.50 

 0. 16 



Millimeters. 

 Length of nooks in front row S 9" 9?^ 



Length of hooks in second row 0. 023 



Length of recurved part of front hooks 0. 061 



Length of ova 0. 035 



Breadth of ova 0. 017 



Length of ovarian masses much greater than ova, circular and oval, with diame- 

 ters as much as 0.1""", others as low as 0.04 mm . 



I confess no small degree of perplexity in identifying this species as 

 E. agilis. The arrangement and character of tbe hooks of the pro- 

 boscis ally it closely with this species and a little less closely with E. 

 claviceps Zeder. Tbe lemnisci are not so long in proportion to the 

 length of the animal as in either of the above-named species. This is 

 about the only character that hints at a probable specific difference 

 which is sufficient to justify the separation of the specimens under con- 

 sideration from either of the above species. The presence or absence 

 of the so-called neck is rather a doubtful feature at best. 



While there are no distinctive characters which seem to my mind to 

 be important enough to justify the erection of a new species, tliere are 

 certainly strong reasons afforded for uniting E. claviceps and E. tu- 

 berosus, which is, indeed, proposed by Dujardin (op. cit., p. 538) and 

 accepted by Diesing, who does not mention E. claviceps in liis revision, 

 and including both under E. agilis Rudolphi. 



In the absence of figures of these species I must content myself at 

 present with referring these specimens to E. agilis. 



With regard to the single specimen fouud in the spiral valve of Car- 

 charias obscurus, it may be well to observe that its presence there may 

 be accounted for by supposing it to have been introduced in the adult 



