KEDESCRIPTION OF TWO SPECIES OF TREMATODE 

 WORMS FROM THE MacCALLUM COLLECTION, WITH A 

 NOTE ON THE FAMILY PRONOCEPHALIDAE 



By Emmeit W. Price 



Zoological Dimsion, Bureau of Animal Industry, United States Department of 



Agriculture 



Recently Dr. G. A. MacCallimi deposited his extensive and valu- 

 able collection of helminths and other parasites in the collections of 

 the United States National Museum, thus making the material avail- 

 able for study. In going over this collection the writer found many 

 of the original specimens of species described by Doctor MacCallura. 

 In view of the fact that some of the species which he described were 

 placed in genera no longer recognized as valid except as collective 

 genera, the writer has undertaken to reclassify the trematodes of 

 this collection and to redescribe those of which the original descrip- 

 tions are inadequate from the viewpoint of present-day standards. 

 This paper contains a redescription of two species of monostomes 

 belonging to the family Pronocephalidae, and in this connection an 

 attempt has been made to revise the family. 



MacCallum (1916) described a monostome from the intestine of 

 the French angel fish, Pomacanthus 'paru, for which he proposed the 

 name Monostomum pomacanthi. An examination of the available 

 specimens of this species shows that it belongs to the genus Pleuro- 

 gonius Looss, 1902, and represents the only species of this genus 

 known from a fish host. 



The specimens available for study are as follows : One specimen, a 

 toto mount stained with carmine (U.S.N.M. No. 8087), labeled 

 "Monostome, int., Angelichthys ciliaris (blue angel fish). Aquar- 

 ium, N. Y., Feb. 5, '14"; 10 specimens (3 slides), stained with hema- 

 toxylin (U.S.N.M. No. 8088), labeled '■'•Monostomum 'pomacanthi., 

 int., French angel fish, Pomaca7ithus jmru. Aq. May 29, '15"; 

 1 badly damaged specimen, a toto mount stained with carmine 

 (U.S.N.M. No. 8089) , labeled " Distome ?, int., Angelichthys isdbelita. 

 Aquarium. May 27, '16 " ; 1 specimen, a toto mounted stained with 

 carmine (U.S.N.M. No. 8090), labeled " Distome, int., Pomacanthus 



No. 2365— Proceedings U. S. National Museum. Vol. 78. Art. 22. 



23921—31 1 



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