NO. 14 MANTER : DIGENETIC TREMATODES OF FISHES 439 



The name Gonocercella indicates the resemblance of the genus to 

 Gonocerca Manter, 1925, The specific name refers to the geographical 

 region. 



Discussion. The most distinctive characters of this genus are the large 

 prostatic vesicle and location of the prostatic gland around it, and the 

 coiled tubular seminal vesicle. The genus differs from Derogenes in these 

 characters and in the preovarian uterus. It differs from Progonus in that 

 the ceca do not unite, from Liopyge in the preovarian position of the tes- 

 tes, from Genarchopsis in the separated ceca and nonfilamented eggs. It 

 has the esophageal pouch (at least, in G. pacifica) of Ophiorchis, but the 

 ceca do not unite and the eggs are nonfilamented. In general appearance 

 it is much like Gonocerca, especially in the short hindbody crowded w^ith 

 reproductive organs and in the preovarian uterus. But in Gonocerca the 

 ovary is pretesticular, and the seminal vesicle and prostatic vesicle are 

 different. 



At least one other species of Gonocercella occurs in the Atlantic. 

 Linton in 1905 described a peculiar distome from Trachinotus carolinus 

 at Beaufort, North Carolina (Linton, 1905, p. 367 and fig. 204). He did 

 not name this trematode but referred to it as "Distomum sp." Linton con- 

 fused gland cells in the cortical parenchyma as vitellaria, and classifica- 

 tion of the species has been impossible from his description. His figure 

 clearly shows the large prostate gland, coiled seminal vesicle, and the 

 same arrangement of organs (except the vitellaria) found in Gonocer- 

 cella. The "lobed" ovary described by Linton evidently is an ovary with 

 closely applied vitellaria. The writer has collected at Tortugas, Florida, 

 from Monacanthus hispidus (Linn.) a specimen (not quite mature) 

 very probably of the same species as Linton's. Its immaturity is perhaps 

 due to the probable abnormal host. In any case, the Atlantic specimens 

 are congeneric with but specifically distinct from the Pacific form. The 

 name Gonocercella atlantica, new species is proposed for Linton's "Di- 

 stomum sp." (Linton 1905, p. 367) with the specific characters noted by 

 him. A further account of this species will be given in a later paper. 



Hirudinella clavata (Menzies, 1791) 



Host: Gymnosarda alletterata (Raf.) 

 Location: Stomach 



Locality: Hood Island, Charles Island, Galapagos 

 Number: 2 from one host, one from another 



