PARASITES OF FISHES OF THE WOODS HOLE REGION. 



469 



A small glol)ular cyst, yellowish, iu one lot, from the viscera and several others from cysts in the 

 liver ill ancjther lot contained minute distomes, which are prohahly young of this species. There was 

 a douhle row of spines around the mouth, ahout 25 in each row. 

 7. DiKliniics (undetermined sjjecies). [PI. xxix, tigs. 824-82!).] Intestine. 



On August 15, 1899, a small lot of distomes were ohtained in wliich there are at least two clistinct 

 species. On account of the small numljer and the unsatisfactory (•on<lition of the preserved material 

 1 shall not assign specific names to them. Tliey were asso(^iated with specimens of 1>. trnnr and 1). 

 tiniutUim. 



A. (Figs. 824, 82<). ) One larger and one smaller specimen. The living worms were yellowish. 

 Body ohlong, appressed, transversely rugose, with minute scattering scale-like sjiines (easily over- 

 looked), (hal .sucker and acetalmlum ahout equal. Aperture of mouth in smaller specimen with 

 notch at anterior horder (not noted in larger specimen ) ; aperture of acetahuluni a little wider than 

 long. Pharynx longer than l)road, apparently protruding into the oral sucker. (Esophagus, if any, 

 short; ii^testinal rami simple, extending nearly to the posterior end. Testes two on median line 

 about middle of body, the anterior testis subglobular, the posterior somewhat tliree-lobed. Seminal 

 vesicle (made out mily in smaller specimen) dorsal to acetabulum; genital aperture on median line 

 immediately in front of acetalmlum; ovary near posterior border of acetidiuJum, a little to left of 

 median line; a seminal receptai'le was made out in the smaller specimen anterior to tlie ovary, and 

 to the left; vitellaria volmiiimius in jKisterior and lateral regions of bodv and extending at least as far 

 forward as the acetabulum, in the smaller specimen as far as the pharynx. Ovum, in larger sjiecimen 

 only, 0.10 and 0.07 in the two principal diameters. 



The following table shows the dimensions in niillinieters, the larger spe{-iiiicii in liiri)entine, the 

 smaller in balsam: 



Length 



Greate.'.t diameter 



Length of anterior .snelcer.. 

 BreatUli of anterior sucker . 



Length ol' aeetabulum 



Breadth of aeetiibulnm 



Length of pharynx 



Breadth of jjliarynx 



Larger 

 speci- 

 men. 



mm. 



a.liO 

 .Sli 

 . ;«; 

 .;is 



.3S 

 .42 



Smaller 

 specimen. 



wm.. 

 1.10 

 .37 



.17 

 .IS 

 .17 

 .■Jl 

 .OS 

 .11 



B. Two specimens stained and mounted in balsam. These agree in the relative proportions of 

 suckers and pharynx, in the position of the genital aperture, and the general arrangement of testes and 

 ovary. The greatest difference is in the character of the vitellaria; other differences may be accounted 

 for by different conditions of contraction. 



Characters common to both are: Acetabulum much larger than oral sucker, Ijroader than long; 

 oral sucker longer than broad; jiharynx nearly as large as oral sucker; icsophagus short; intestinal 

 rami simple, reaching nearly to posterior end; testes two on median line in about the jjosterior third 

 of body, the anterior testis immediately preceded by the ovary, which lies a little to the riglit of the 

 median line; genital aperture a short distance in front of acetabulum, to the left of the median line; 

 the radiating muscles of the cirrus bulb are distinctly seen in ventral \'iew upon f<icusing with a high 

 power. 



a. (Fig. 327. ) This specimen was probably killed while flattened out under pressure. The body is 

 smootli, the intestfnal rami thin-walled and inflated. There is a vitelline reservoir immediately in 

 front of the ovary, into which two anterior and two posterior vitelline ducts empty. The vitellaria 

 are rather irregular small granular masses at the posterior end of the body and along tlu^ lateral margins 

 nearly to the acetabulum. The two testes and ovary are each subglobular. 



h. (Figs. 328, 829. ) This specimen is much contracted. The body is transversely rugose, and the 

 posterior region, when strongly magnified, is seen to be beset with minute, bristle-like spines. The 

 intestinal rami are slender, (jut thick-walled. The vitellaria are at the po.sterior eiul of the bod}' and 

 along the margins as far forward as the pliarynx; the granular masses larger and more crowded than 

 in a. Testes and ovary broader than long. 



