440 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



Identification of this species was made on the size and shape of the 

 body, on the separate sex openings on the genital papilla, and on egg 

 size (31 by 23 fj.). Specific identification is difficult in this group. While 

 G. alletterata is apparently a new host, this trematode is known from a 

 number of related fishes. 



Hirudinella beebei Chandler, 1937 



Host: Acanthocybium solandri (Cuv. and Val.) 



Location: Stomach 



Locality: Galapagos Islands 



Number : Several collected ; usually one to 3 present in a host 



These giant trematodes, probably the largest species known, have 

 been reported from the wahoo (Acanthocybium petus) by Chandler 

 (1937) and from A. solandri from Bermuda and Yucatan by NigrelH 

 and Stunkard (1937). The author has a specimen collected by Dr. A. O. 

 Foster from A. solandri from Panama Bay. The trematode evidently has 

 a wide distribution in both oceans. 



Living specimens when extended (stretched) attained a length of 

 125 mm, when contracted only about 40 mm. My largest preserved speci- 

 men is 65 mm, the same length reported by Nigrelli and Stunkard. 



Syncoeliidae Dollfus, 1923 



Paronatrema mantae, new species 

 (PlateSO, figs. 129-133) 



Host: Manta birostris (Walbaum) 

 Location : External, on the skin 

 Locality: Bahia Honda, Panama 

 Number: 4 specimens 



This trematode furnishes additional data on the little-known genus 

 Paronatrema Dollfus, 1937. From its study, the following generic diag- 

 nosis is proposed. 



GENERIC DIAGNOSIS OF PARONATREMA 



Syncoeliidae. Large-sized distomes with unspined skin ; suckers large, 

 forebody narrow, hindbody wide. Acetabulum with a ring of small acces- 

 sory suckers; a ring of accessory suckers may also occur in oral sucker. 

 Glands in forebody. Intestinal ceca sinuous, probably opening into ex- 



