66 Roosevelt Wild Life Bulletin 



to the second were a large number of minute distomes of the species 

 Caecincola parzndus ( ^Marshall and Gilbert), which were found in the 

 pyloric caeca and the duodenum and which measured about half a 

 millimeter in length. This distome has also been obtained in the 

 same fish in \"\'isconsin. 



Micropteriis dolomicu (Lacepede) : Small-mouthed Black Bass. 

 Four fish (Nos. 1227a, 1228, 123311, 1268a) were examined which 

 were found to be rather heavily infected with Trematodes, Cestodes 

 and Acanthocephala. No Nematodes were found. 



One species of Trematode was taken. The duodenum and 

 pyloric caeca of all the fish were thickly infected with a minute 

 •distome belonging to the species Crepidastomum cornutum (Os- 

 born), the length of which, compressed and mounted, averaged one 

 millimeter. This worm was also found in the rock bass in Oneida 

 Lake. 



One species of Cestode was found. The liver and the fatty tissue 

 surrounding the pyloric caeca of' all the bass examined contained a 

 large number of large cysts of a proteocephaloid tapeworm. The 

 worm taken from its cyst and extended measured about 8 mm. 



Two species of Acanthocephala were taken from the intestines of 

 three of the bass examined. One of these belongs to the genus 

 Neoechinorhynchus (X-'ials "ji. 75, 182, 183), from one to a dozen 

 worms being found in each fish. Associated with these were also a 

 few worms belonging to the genus Echinorh\nchus (Vials 73, 75, 77, 

 182, 183 j. 



Erimyzon succtta oblong us (']\Iitchill) : Chub Sucker. One fish 

 was examined (No. 1263) and the only internal parasites found were 

 a single Acanthocephalan belonging to the genus Echinorhynchus and 

 a single Cestode belonging to an undetermined genus. 



Pei-ca Havescens (Mitchill) : Perch. Eight fish were examined 

 and were not found to be badly infested with parasites. Five of them 

 contained Trematodes and four contained Nematodes. No Cestodes 

 or Acanthocephala were taken. 



Two species of Trematodes were found. One of these is Clino- 

 stomiun marginatum (Rudophi), which was taken from two perch 

 (No. 1225), encysted just beneath the skin on the pectoral fins and 

 at the base of the tail. These worms were immature individuals, the 

 fish being their intermediate host. The adult worms live in the 

 oesophagus and pharynx of herons and other fish-eating birds which 

 become infected with the parasites by eating the fish. The presence 

 of the conspicuous cysts or " grubs." as they are called by fishermen, 

 usually renders the fish unsalable in the markets and grubby fish are 

 thrown away by amateur fishermen, notwithstanding the fact that 

 thev are entirelv harmless and could not injure anyone eating them 

 with the flesh of the fish. Clinostomum is thus of economic signi- 

 ficance, especiallv throughout the summer and early fall when it is 

 most ntmierous. 



