510 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.2 



Genus NIPPORHYNGHUS Chandler, 1934 



Chandler (1934, p. 355) recognized Nipporhynchus as a new genus 

 based on the concept of Rhadinorhynchus katsuwonis Harada, 1928. To 

 this genus he tentatively ascribed R. ornatus Van Cleave, 1918, because 

 details of structure were too imperfectly known to warrant unqualified 

 assignment of the species in his new series of generic concepts. A number 

 of specimens in the collections of the Hancock Pacific Expedition agree 

 with the original material of R. ornatus. Fortunately, among these one 

 male individual is included. Since males were previously unknown and 

 since some of the most stable generic characters in this family rest on 

 characteristics of the male, this material offers the first opportunity for 

 confiiTning Chandler's tentative assignment of R. ornatus to the genus 

 Nipporhynchus. 



Previously, the only concept of R. ornatus was based on the rather 

 inadequate description given by Linton (1892). The discovery of addi- 

 tional specimens in the Hancock Expedition collections enables the writer 

 to give a more comprehensive description of this species. In doing so it has 

 become evident that Nipporhynchus katsuwonis, described as a new spe- 

 cies by Harada (1928), cannot be differentiated from N. ornatus and 

 must fall as a synonym. Detailed comparisons on which this conclusion 

 is based are shown in Table I. Since Chandler (1934) had cited N. 

 katsuwonis as genotype by original designation, its valid synon3an N. or- 

 natus (Van Cleave, 1918) becomes the genotype of Nipporhynchus. 



The present writer cannot agree with the position of Yamaguti 

 (1938, p. 271), who states "There is no sound reason for separating this 

 species [R. katsuwonis] from Rhadinorhynchus Liihe, 1911, as type of 

 Nipporhynchus Chandler, 1934." The genus Nipporhynchus is a valid 

 concept under the family Gorgorhynchidae as expressed by Van Cleave 

 and Lincicome (in press). 



Generic diagnosis. Gorgorhynchidae with long proboscis, armed 

 with many longitudinal rows of hooks which are longer and stouter on 

 ventral surface than on dorsal, basal row forming a complete circle. 

 Proboscis receptacle double walled. Anterior body region beset with 

 spines which may be in a single or double field. Lemnisci ribbon shaped, 

 about as long as proboscis receptacle. Testes elongate. Cement glands 4 

 in number, elongated, cylindrical or club shaped, and may be paired. 



Type species. Nipporhynchus ornatus (Van Cleave, 1918). 



The only representative of this genus encountered in this study is 

 the genotype. 



