92 THE AMERICAN M0NTHL5r [April, 



Family : Sethocyrtida. 



5. Dictyocephalus microstoma, n. sp. Fi-equent. 6. Dicty- 

 ocephalus macrostoma, n. sp. Very frequent. 



Family : Theocyrtida. 



7. Theocampe sphasrocephala, n. sp. Not frequent. 8. Tri- 

 colocapsa salva, Riist. Frequent. 9. Tricolocapsa thoracica, n. 

 sp. Not frequent. 10. Tricolocapsa dowlingi, n. sp. Not 

 frequent. 11. Tricolocapsa selwyni, n. sp. Not rare. 



Family : Lithocampida. 



12. Dictyomitra canadensis, n. sp. Not frequent. 13. Dic- 

 tyomitra multicostata, Zittel. Frequent. 14. Dictyomitra 

 polvpora, Zittel. Frequent. 15. Stichocapsa tyrrelli, n. sp. 

 Not rare. 16. Stichocapsa dawsoni, n. sp. Not frequent. 



The first species belongs to the order Sph^roida ; the second 

 and third to the order Prunoidea, and all the others to the order 

 Cyrtoidia. 



1. Caryosphaera aequidistans, n. sp. — Shell composed of 

 five concentric spheres, two medullary and three cortical, each 

 with about equal radial proportions. All the spheres with regu- 

 lar, circular pores, two to four times as wide as the bars, increas- 

 ing in size from the centre towards the smooth surface. 



2. Cenellipsis hexagonalis, n. sp. — Ratio of the longer 

 axis to the shorter, 2:1. Pores regular, circular, about as wide 

 as the bars, thirteen to fifteen on the half equator. The per- 

 imeter of a longitudinal section is roundish hexagonal. Surface 

 smooth. 



3. Prunulum calococcus, n. sp. — The ellipsoidal cortical 

 shell thin-walled, smooth, with regular circular pores, about as 

 wide as the bars. Ratio of the major axis of the ellipsoid to the 

 minor, 3:2. Both medullary shells large and spherical, with 

 large circular pores. 



4. Cyrtocalpis crassitestata, n. sp. — Shell infundibuli- 

 form, very thick, with regular circular pores of equal size, and 

 about as wide as the bars. Mouth large, simple, wider than the 

 length of the shell. Surface smooth. 



5. Dictyocephalus microstoma, n. sp. — Shell thin- 

 walled, smooth, collar stricture not apparent. Cephalis sub- 

 spherical, hyaline, without pores. Thorax inflated, subspheri- 

 cal, with regular circular pores, about as wide as the bars, in 

 twenty oblique rows. Mouth constricted, only one-third as 

 wide as the thorax, without peristome. 



6. Dictyocephalus macrostoma, n. sp. — Shell thin- 

 walled, smooth, without collar stricture. Cephalis subspherical, 

 hyaline, without pores. Thorax roundish, urceolated, with 

 regular circular pores, about as wide as the bars, in fifteen to 



