DEVONIAN SECTION OF ITHACA, N. Y. IOl 
described by Conrad as Cypricardites carinijera and that named and 
figured by Vanuxem as Cypricardites chemungensis undoubtedly 
occur at Chemung Narrows in the typical Chemung fauna, the char- 
acters by which they may be discriminated from other representa- 
tives of the same genus at horizons below the range of other typical 
Chemung species are too vaguely established to make certain that 
the species is confined to the Chemung formation. Closely related 
species of the genus do certainly occur below and probably above 
the Chemung formation. 
Mytilarca chemungensis.—As a genus Mytilarca ranges through- 
out the Devonian and upward into the lower formations of the carbon- 
iferous and both the elongate form M. chemungensis and the 
shorter form M. carinata are frequently met with in the Chemung 
rocks. Several other species have been described from rocks of 
other than the typical section referred to the Chemung formation. 
The forms from the Ithaca and lower horizons most closely resembling 
the Chemung species are more gibbous, and upon this character and 
the more narrow form of the Chemung representatives of the genus 
they may be distinguished. So that this species and its closely related 
species may be used as strongly suggesting, if not strictly indicative, 
of a Chemung horizon. 
One of the localities (2517) referred to by J. M. Clarke in the 
paper before mentioned as containing Pterinea chemungensis is also 
reported as holding Mytilarca chemungensis. Another significant 
species is Leptostrophia nervosa. ‘The combination is one suggesting 
the Chemung fauna but the horizon is not clear. Clarke reports the 
locality as “‘ Ithaca beds.” * 
Productella lachrymosa (Con.) and P. lachrymosa var. lima (Con.). 
—There is no doubt that forms of the genus Productella falling 
strictly under the description of Conrad’s species Strophomena lachry- 
mosa are present in the typical Chemung zone at Chemung Narrows 
as well as the variety S. lima. ‘The question may be raised, however, 
whether this species is diagnostic of the Chemung fauna in New 
York state. Examination of a large number of faunules containing 
representatives of the genus demonstrate that the prominent char- 
acteristics of P. lachrymosa, 1. e., the ventricose general form, large 
tN. Y. State Mus. Bull., 82, p. 60. 
