Wetter — Kinderhook Faunal Studies. 153 



Length of type specimen 14 mm., height 9| mm., con- 

 vexity of one valve about 2 mm. 



Remarks. This little shell seems certainly to be cogeneric 

 with those species in the Spergen Hill fauna of Indiana, and 

 with those in the New York Devonian faunas, which are 

 referred to the genus Microdon. 



GASTEROPODA. 

 Holopea conica Win. 



PI. XII. f. 4-7. 



Shell small, never exceeding 10 mm. in height and 

 usually not more than 5 mm. Spire elevated ; whorls grad- 

 ually and regularly increasing in size, probably about seven 

 or eight in the adult shells, though usually not more than 

 four or five are preserved, the apical ones being destroyed. 

 Suture distinct, moderately impressed. Aperture subcircular 

 in outline, somewhat angular posteriorly, but regularly 

 rounded in front. The outer lip thin, inner lip slightly 

 thickened, surface of shell smooth. The dimensions of one 

 of the best preserved specimens, the type of Holopella mira 

 Win., are, height 5i mm., diameter of body whorl 3 mm. 



Remarks. Winchell has described separate individuals of 

 a little coiled shell, which occurs gregariously in this stratum, 

 as three distinct species, Holopea conica, Holopea subconica, 

 and Holopella mira, but a careful examination of all the type 

 specimens and numerous others has led to the decision that 

 all of them constitute a single species, the various specimens 

 exhibiting different stages of growth. The proper generic 

 reference of the species is not certain, but it does not have 

 the circular aperture of Holopella, and is for the present re- 

 tained in the genus Holopea, though the adult shells possess 

 a more elevated spire than is usually present in members of 

 that genus. The specific name retained is conica, that being 

 the first species described, although all of them were pub- 

 lished in the same paper. 



Loxonema sp. undet. 



A single imperfect individual of a species apparently be- 

 longing to this genus, has been noticed. When complete it 



