372 



THE AMERICAN NATURALIST [Vol. XL 



Of small size. Common in Hummock Pond and in sphagnum 

 swamps. 



4. Centropyxis aculeata ecornis Ehrenberg. Length 94 fiy 

 breadth 78 /i; apertuce 26 /«. From sphagnum. 



5. Quadrula symmetrica Schul. Length 68 ,u; breadth 38 

 aperture 13.5 fi. 



This species occurred but once and then in considerable num- 

 bers. It was from bog moss material near the town. The speci- 

 mens were very uniform in size and were small. 



6. DifElugia globosa Dujardin. Diameter 58-65 /i. Hum- 

 mock Pond. 



7. Difflugia pyriformis Perty. Length 90-102 /jl; breadth 

 45-54 fi; aperture 21-24 /jl. 



Small. Common in Gibb's and Wigwam Ponds and in sphag- 



8. Difflugia acuminata Ehrenberg. Length 125-168 breadth 

 40-71 «; aperture 12-27 



Of small size. Wigwam Pond and from bog moss. 



9. Difflugia corona Wallich. The only specimens referable to 

 this species were from Wigwam Pond. These were of the usual 

 shape but somewhat undersized and their shells instead of being 

 composed of sand grains were almost entirely made up of diatom 

 frustules. Diameter 112-132 pi; aperture 50 fi. 



10. Difflugia constricta Ehrenberg. Length 60-87 n; breadth 

 36-46 aperture 18 fi. Specimens of this species were found in 

 but one lot of material and in this they were common. They 

 were from bog moss near the town. The specimens were all 

 undersized. 



11. Difflugia lobostoma Leidy. Length 84//; breadth 52 n; 

 aperture 13 «. From sphagnum. 



12. Lecquereusia spiralis Ehrenberg. Length 94 /i; breadth 



This species was found in material from the north head of Hum- 

 mock Pond only. The shells were composed of the peculiar pel- 

 lets characteristic of this species. The specimens were small for 



13. Euglypha alveolata Dujardin. Length 90 /<; breadth 75 

 aperture 23 



This species was met with but once, viz., in material from Wig- 



