254 ^- GOTO. 



Analytical Key to the Species described. 



Body symmetrical except in a few cases. 



f ^ With a pair of spheroidal suckers witliin the month, 

 and with numerous, small, flattened suckers on both 

 sides of the caudal disc ; body sometimes asym- 

 metrical MICROCOTYLE. p. 185. 



""^Body symmetrical, about 3.2 mm. long; caudal 

 disc distinctly separated from the body proper, 

 about T the total length of the body ; with about 

 25 suckers on each side ; genital atrium armed 



with slightly curved, conical spines M. caudata. p. 18(î. 



"-Body symmetrica], slender, about 5.5 mm. 

 long ; caudal disc distinctly set off from the 

 body proper, about Jj the total length of the 

 body ; suckers about 29 on each side ; genital 

 atrium armed with slightly curved, conical 

 spines generally longer than those of 



jl/. caudata M. scbastis. p. 187. 



"^Body symmetrical, slender, about 4 mm. long; 

 caudal disc distinctly set off from the body 

 proper, a little longer than \ the whole length 

 of the body ; suckers about 50 on each side ; 

 genital atrium armed with conical spines about 



0.005 mm. long M. elegans. p. 188. 



**Body slightly asymmetrical, elongated, thick, 

 6-lOmm. long; caudal disc not distinctly separat- 

 ed from the body proper, somewhat longer 

 than ;\ the total length of the body ; suckers 

 about 42 on one side and 23 on the other ; 

 intestinal branches forming a complicated 



