Entozoa of !>ri(i.'</i Marine Fi'shfis. 87 



lu'liiiid tlie vciitial siiekL-r and markedly oblunie ; also l)v 

 the relative sizes of the suekers. From /7. Ln/iti it differs 

 in the ienj^th of the cesophagus, in the sliortuess of the pars 

 prostatiea, and in the forward ])osition of the vesieula semi- 

 nalis and teste«i. It diflt-rs from both in the length of the 

 appendix. 



Mature examples were found in the sand-eel, varying in 

 length (ineludiug appeniiix) from r5-2 5 mm. Of this the 

 appendix often comprised as much as ^ (i. e. ^ of the rest of 

 the body) ; usually somewhat smaller, but never less than 

 half as long as the rest of tiie body. The examples from the 

 haddock and ihe halibut agrc e in this lespect. Tiie b(Kly is 

 not so attenuated as in the form from Clupea hnrenyus, the 

 breadth being •37-'. "38 mm. just behind the ventral sucker 

 and 42- b7 in front of the appendix. The neck (distance 

 between centres of suckers) is also much longer than in the 

 above form, being ;\ of the body-length. The oral sucker 

 has a diameter of 'll-'lS mm. and the ventral a diameter of 

 • 10-26 mm., so that the relative size is from ^ to f,, more 

 usually the latter. The pharynx is contiguous with the oral 

 sucker and measures "00 x '07. There is a distinct oesophagus, 

 about as long as or longer than the pharynx. The intestmal 

 diverticula may extend a considerable distance into the 

 appendix, but often stop short of it. The cuticle of the 

 body is ringed, but the rings become faint towards the 

 appendix. The striations on the latter are not very distinct. 

 It is usually divided into two portions of almost equal length, 

 the posterior of which becomes invaginated within the other 

 when the appendix is retracted. 



The genital aperture occupies the same position as in the 

 preceding species; the genital sinus is not quite so long. 

 The pars prostatiea is shorter and the seminal vesicle, which 

 is double, is immediately behind the ventral sucker. The testes 

 are globular or ovoid and are not far behind the seminal 

 vesicle ; somewhat obliquely situated, the left is almost 

 entirely in front of the right. They have a diameter of 

 •10-*16 mm. The ovary is ovoid, the long axis being trans- 

 verse, and measures "Il-'IG mm. X "09 mm. The yolk-glands 

 arc behind the ovary and contiguous with it; they are usually 

 slightly lobed as in the preceding species. The uterus is 

 voluminous and may extend into the appendix. The ova 

 are numerous and measure •022-031 mm. x 009-013 ram. 

 The specimens from Gadus (Bglefinus present slight 

 variations from the above and tend more to H. appendi- 

 culatiis, but tliey certainly cannot be included under that 

 s[)eeies according to Liihe's definition. 



