POLYGYRA ALBOLABRIS AND LIMAX MAXIMUS 261 



cecal diverticula, a longer and stouter coiled one, and a shorter 

 one with globular head, which during life is concealed in the first 

 coil of the intestine. 



It is a remarkable fact that, while the flagellate form of the 

 penis, and the accessory organs, viz, the dart sac and multifid 

 vesicles, are very common in European species of Helix, they 

 are very rare in east American forms. "A flagellate form of the 

 penis does not exist in a single one of the latter forms. An 

 analogue of the multifid vesicles exists in only four of the species 

 occurring in - New York. In Gastrodonta inter texta 

 and (t. g u 1 a r i s there is a single pair of follicles. In G. 1 i g e r a 

 and G. suppressa there is but one short follicle. The dart 

 sac exists in the above-named species. 



Description of a new species of entozoa 



BY DR JOSEPH LEIDY 



Plate IS, fig. 6 



In September 1846 I first gave an account in our proceedings 

 of a new genus and new species of Entozoa, inhabiting the fluid 

 contained in the spermatheca of Helix albolabris, H. tri- 

 dent a 1 i s and H. a 1 1 e r n a t a. Since then I have verified 

 the observation, and also have detected it in other species of 

 Helix, viz, e 1 e v a t a and thyroides, and have also de- 

 tected it in an allied genus, Bulimus decollatus. The 

 name which I gave it at that time I was not aware had been pre- 

 viously applied to a genus of Insecta brachelytra, with 

 the only difference of the latter having a neuter termination. I 

 will therefore change the name. 



Cryptoicus minutissimus; forma mutabilissima; organisatione interno cellu- 

 larium et granulosum, C. h e li c i s. Coloris expers; forma plerumque elongata, fusiforme, 

 vel ovata ; caudis duabus adversis, una longior quam altera. Structura interno sto- 

 machos duos et granulos numerosus parvos exhibit. Long _i-. __-!--- lin. Habitat 

 in spermatheca Helices albolabris, tridentata et Bulimus decollatus. 



This singular entozoon is a polygastric animalcule. Its varied 

 forms and movements are curious to observe; at one moment glo- 

 bulose, then oval, ovate, fusiform, sigmoid, crescentic, etc. It 

 appears as if it would outvie the kaleidoscope in its changes. 

 Sometimes it collects in bunches, adhering by the end of the 

 cauda to each other, and frequently it may be observed to contract 

 upon either of the large cellules, causing them to project beyond 



