THE ACANTHOCEPHALA COLLECTED BY THE 

 ALLAN HANCOCK PACIFIC EXPEDITION, 1934* 



(Plates 51-55) 



Harley J, Van Cleave 



University of Illinois 



Through the courtesy of Dr. H. W. Manter and Dr. Irene McCul- 

 loch, I have had the opportunity of studying the Acanthocephala which 

 Dr. Manter collected when he accompanied the Hancock Pacific 

 Expedition of 1934 to the Galapagos Islands. The collection, although 

 relatively small, is of great significance because 4 new species of Acantho- 

 cephala have been encountered and further biological and distributional 

 data have been added for 3 previously known species. All of the new 

 forms encountered are from fish hosts. They are Gorgorhynchus lepidus, 

 Gorgorhynchus clavatus, Filisoma bucerium, and Tegorhynchus pec- 

 tinarius, which are described in this report. The forms for which addi- 

 tional data become available are Nipporhynchus ornatus (Van Cleave, 

 1918) from a fish host and Southwellina hispida (Van Cleave, 1925) 

 and Centrorhynchus spinosus (Kaiser, 1893) from avian hosts. 



In the course of this study it is pointed out that Gorgorhynchus gibber 

 is a synonym of G. medius, so the latter becomes type of the genus. 

 Similarly, it is shown that Nipporhynchus katsuwonis is a direct synonym 

 of N. ornatus, whereby ornatus becomes the type of Nipporhynchus. 



Genus GORGORHYNCHUS Chandler, 1934 



Chandler (1934, p. 356) applied the name Gorgorhynchus to a 

 generic concept based on Rhadinorhynchus medius (Linton, 1907) and 

 on G. gibber, which he designated as type of the genus and described in 

 the same paper. In his original description. Chandler expressed the 

 feeling that G. gibber and G. medius resemble each other so closely that 

 "there might even be some question of their specific distinctness." In 

 establishing the status of G. gibber, he made numerous comparisons with 

 observations on G. medius published by Linton (1907), and, although 

 he showed that some of Linton's observations were in error, he proceeded 



* Contributions from the Zoological Laboratory of the University of Illinois, 



^^ ^,0-'nf^j> 



