NO. 14 MANTER : DIGENETIC TREMATODES OF FISHES 343 



ally reach the posterior testis by some distance (it did so in only one of 16 

 specimens). Genital atrium large, atrial gland well developed; genital 

 pore some little distance in front of posterior end of body. Several speci- 

 mens showed recently formed spermatophores. Excretory pore ventral; 

 excretory vesicle conspicuous in most specimens, extending forward to 

 posterior limit of the gonads. 



The name gonoderus {gono = gonads; derus = neck) refers to the 

 location of the gonads in the neck region. 



Comparisons. This species is notable for the far anterior location of 

 the mouth and of the reproductive organs. The body seems to have elon- 

 gated posteriorly, leaving these organs anterior, but they are relatively 

 close to the anterior end as well as being very far from the posterior end. 

 The species differs from all others in the genus in this location of the go- 

 nads, and from most other species in the fact that the uterus does not ex- 

 tend anterior to the ovary. 



Prosorhynchus pacificus, new species 

 (Plate 33, fig. 17) 



This species was collected four times, as follows: 

 Host Locality 



Mycteroperca olfax (Jenyns) Albemarle Island, Galapagos 



(type host) (type locality) 



Mycteroperca xenarcha Jordan Albemarle Island, Galapagos 



Unidentified grouper James Island, Galapagos 

 Location: Ceca 



Number: Several to many. In the case of both M. olfax and 

 M. xenarcha, Prosorhynchus ozakii also occurred in 

 small numbers. 



SPECIFIC DIAGNOSIS OF PROSORHYNCHUS PACIFICUS 



Body elongate, about equally wide along most of its length, blunt at 

 anterior end, tapering to a rounded, somewhat pointed posterior end. 

 Length 1.206 to 1.444; width 0.300 to 0.397. Rhynchus large, muscular, 

 cone shaped, longer than wide, width 0.172 to 0.232. Mouth between ^ 

 and Yz body length from anterior end; sac-shaped intestine extending 

 forward; pharynx 0.054 to 0.061 in diameter. Gonads near midbody. 

 Ovary spherical, at pharynx level, to the right, overlapping anterior tes- 

 tis; vitellaria in two widely separated lateral groups, extending from 

 about the level of the ovary halfway to anterior end of body; follicles 



