334 NEW Y ORK STATE MUSEUM 



macrochilina Bayle. 1 880 

 Macrochilina pygmaea sp. nov. 



Plate 18, fig. 17-19 



This is a minute shell, but has been found frequently, and in all 

 instances its size and proportions are uniform. It has a subpyriform out- 

 line, very short and blunt spiral of three to four volutions, the surfaces of 

 which slope quite obliquely, the suture being but slightly impressed. The 

 body whorl is very large and long, being five or six times the length of the 

 spiral. Its form is obliquely ovoid, extended below, the curve of the sur- 

 face being quite regular. At the aperture more than one half the volution 

 is overlapped. The aperture itself is narrow, elongate, regularly contracted 

 below, and the peristome has a thin outer edge and a somewhat thickened 

 columella beneath. Shell nonumbilicate. Surface quite smooth. Average 

 length 2 to 3 mm. 



Habitat. Genesee province ; Naples subprovince. In the concretions 

 on Honeoye lake, and in the Styliola limestone, Canandaigua lake. 



Macrochilina seneca sp. nov. 



Plate 18, fig. 15, 16 



Shell small, oblique with relatively short spire and broad body whorl. 

 Volutions three, overlapped for about one half their hight, depressed con- 

 vex. Spire not more than one half the hight of the body whorl. The final 

 whorl expands rapidly, becoming convex ovoid and rotund but not ventri- 

 cose, and its aperture is elongate oval. Surface of all whorls covered with 

 fine and obscure concentric growth lines, which are occasionally interrupted 

 by deeper furrows. 



Dimensions. The largest of these specimens has a hight of 4 mm, 

 basal width of 3.5 mm. 



Habitat. Genesee province; Naples subprovince. In the Styliola 

 limestone at Seneca point, Canandaigua lake. 



