492 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



[40] 



condition along with some more visual host which had been eaten by the 

 shark a short time before the latter was examined. However interest- 

 ing this supposition may be, it is hardly necessary, as there is no rea- 

 son why C. obsourus should not be a proper host of E. agilis. 



Echinorhynchus acus Budolphi. 



[Plate V, Figs. 7-13.] 



Rudolphi, Wiedmann's Arehiv., ii, 2, 51 ; Entoz. Hist., ii, 279 ; Synops., 71 and 324. 

 Zeder, Naturg., 150. Westrumb, Acauthoceph., 24. Siebold, in Burdacb's Physiol., 2, 

 Aufl., ii, 196(ovula4). Drummond, Cbarlswortb's Mag. of Nat. Hist., ii, 516. Belling- 

 bam, in Annals of Nat. Hist., xiii, 25G. Dnjardin, Hist. Nat. des Helminth., 540. 

 Crepiin, Nov. Obs., 43, and in Ersch. and Grub. Encyclop., xxxii, 284. Leidy, in 

 Proceed. Acad. Phila., viii, 43. Van Beneden, Mem. Vers. Intest., 279-287 (develop- 

 ment). 



For detailed synonymy and habitats, see Diesing, Syst. Helm., ii, 39-40, and Revis, 

 d. Rhyngodeen, 747. 



Proboscis linear with about twenty series of hooks ; neck none ; body 

 long, greatest width a short distance back of proboscis, subattenuate 

 posteriorly, bluntly rounded at posterior end. Length 27 to 81 ,um (Du- 

 jardin), breadth 2 mm ; males half as long as females ; color usually white. 



"The color is very various but generally white wheu distended, 

 though frequently accompanied at the same time by a tinge of orange, 

 pink, or cinereous. Sometimes the whole animal is reddish orange 

 (especially the male), and sometimes the whole is ivory white with a 

 solitary minute crimson dot here and there" (Drummond). 



Some specimens flat, thin, with regular outline, others cylindrical with 

 irregular transverse rugae. All the specimens noted by me were white 

 or faintly tinged with yellow. 



The following measurements were made on alcoholic specimens : 



Dimensions. 



Length of specimen 



Length of proboscis 



Breadth of proboscis 



Length of proboscis sheath 



Breadth of proboscis sheath 



Breadth of body, anterior 



Breadth of body, antero-median 



Breadth of body, near posterior end 



No. 1, ? No. 2, ? 



No. 3, cf 



Length of lougest living specimen, 60' 



Dimensions. 



Lorigest diameter of ovarian masses 

 Shortest diameter of ovarian masses 



Length of ova ■ 



Breadth of ova 



Length of embryo 



Breadth of embryo 



Millimeters. 



0.11 



0.075 

 0.13 

 0.03 

 0. 008 

 0.017 



Millimeters. 



0.07 



0.05 



0.114 



0. 055 



0.08 



0.018 



Millimeters. 



0.08 

 0.07 

 0. 112 

 0. 023 

 0.076 

 0.015 



