28 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



Subfamily Prosorhynchinae Nicoll, 1914 



Genus PROSORHYNCHUS Odhner, 1905 



PROSORHYNCHUS CRUCIBULUM (Rndolphi) 



Plate 18, Figttbes 240-242 



Prosorhynchus crucihulum (Rudolphi), Nicoll, Parasitology, vol. 3, pp. 352-354, 

 fig. 7, 1910. 



Two gasterostomes from the conger eel, mounted in balsam, al- 

 though showing the anatomy incompletely on account of the masses 

 of ova which fill the greater part of the body back of the vitellaria, 

 agree closely with this species as it is described by Nicoll. The body 

 is covered with minute spines and does not vary much in breadth; 

 the breadth at the widest part approximately one-third the length. 

 The anterior sucker is a comparatively large muscular structure, to 

 which Nicoll gives the appropriate name "rhynchus." It tapers to a 

 wedge shape posteriorly and reaches about to the anterior follicles of 

 the vitellaria. The follicles of the vitellaria are irregular in shape, 

 and form an arcuate, transverse cluster in front of the intestinal 

 caecum and anterior folds of the uterus. The ventral sucker is a little 

 back of the middle, and the intestinal caecum is directed forward. 

 In one of the specimens the testes are opposite, the ovary lies at the 

 dorsal border of the right testis, and the cirrus pouch impinges on 

 the posterior edge of the right testis. In the other specimen the 

 testes are crowded to the right side and the cirrus pouch is on the 

 left side, its anterior end about on a level with the left testis, which 

 is at the anteromedian border of the right testis. The ovary is at 

 the anterior border of the right testis, its posterior border also touch- 

 ing the left testis, and its anterior edge on a level with the ventral 

 sucker. The ova have thickish shells, but are somewhat distorted 

 when closely packed together ; average size about 0.036 by 0.024 mm. 



Host. — Conger eel {Conge?' conger). 



Table 7. — Measurements of two specimens of Prosorhynchus crucihulum in 



'balsam 



Measurement 



Length 



Breadth 



Anterior sucker, length 



Anterior sucker, breadth 



Diameter of ventral sucker 



Anterior end to vitellaria 



Anterior end to ventral sucker 



