348 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



differs from Apocreadium in the characteristic folds of the forebody and 

 in the unbranched lymph vessels. Body spines are better developed in 

 Choanodera. The details of the reproductive system are practically identi- 

 cal in the two genera, differing only in specific characters. 



The discovery of still another Allocreadid-like distome vrith lym- 

 phatic vessels increases the known number of such genera to five : namely, 

 Petalocotyle, Megasolena, Hapladena, Apocreadium, and Choanodera. 

 Carassotrema must be considered a related genus. This group of trema- 

 todes shows relationship to the amphistomes, on one hand, and to the 

 Anallocreadiinae and Lepocreadiinae, on the other. 



Apocreadium mexicanum Manter, 1937 



Host: Labrisomus xanti Gill 

 Location : Intestine 

 Locality : Tangola Tangola, Mexico 

 Number: 18 specimens from a single host 



Apocreadium longisinosum Manter, 1937 



Hosts: Cheilichthys anniilatus (Jenyns) 

 Spheroides angusticeps (Jenyns) 

 Location: Rectum 

 Locality: Galapagos Islands 

 Number: 2 to 10 in a host, total of 15 collected from 3 hosts 



Allocreadiidae Stoss., 1904 



Lepocreadium bimarinum, new species 

 (Plate 34, figs. 19-21) 



Hosts: PiTtielometopon pulcher (Ayres) (type host) 



Bodianus diplotaenia (Gill) 

 Location : Intestine 

 Locality: Cerros Island, Mexico (type locality) 



Socorro Island, Mexico 

 Number: 5 specimens from a single P. pulcher; 2 to several 



collected from each of 3 B. diplotaenia 



The following diagnosis is based chiefly on 4 specimens from P. pul- 

 cher and one from Lachnolaimus inaximus (Walbaum) from Tortugas, 

 Florida. The specimens from Bodianus were dead when collected and 

 partly macerated, although they agreed in every significant detail with the 

 forms from Pimelometron. 



