38 



Report of the State Geologist. 



extremities, bears all the characters distinctive of the common expression of 

 the species in its occurrence through the Ithaca fauna of Cortland, Tompkins 

 and Schuyler counties. The mucronate extension of the hinge is by no means 

 a persistent feature of typical forms; indeed, the name itself was based upon 

 forms in which this extension is but slight, and it is not unusual to meet witb 

 individuals in which there is no evidence (ff any lateral prolongation of the 

 hinge angle ; the condition of the shells at the horizon under consideration. 

 But this mucronation of the shell may be carried to a great extreme and afford 

 unprecedented illustration of such configuration among the stropheodontoid 

 brachiopoda. A specimen from Spafford, Onondaga county, 375 feet above 

 the TuTly limestone and associated with Tornooera% Wbia/rigula/re, Buchiolo 

 speciosa, Pa/racyclas lirata, etc., bears at each angle a curving cardinal spine 

 having fully as great length as the shell itself (Figure 3). Several specimens 



Figcrk 3. Leptostrophia mucronata, Conrad (sp.). Spafford, N. Y 



from that locality all show the same character. Close analy>is of this feature 

 is needed to show whether its variations possess a definite local or time value. 

 Suffice it to say that in all observed specimens from the Cowles hill section 

 the shells are small and the angles not produced. 



Of the specimens referred to Spirifer Iwvis, nine have been seen from the 

 tw o stations 3 and 4. These are, for the most part, internal casts, one a cast 

 of the exterior affording the superficial characters of the shell, and one or two 

 partially exfoliated shells. Upon careful comparison of these specimens with 

 the species as it occurs at its typical locality, Ithaca, involving close analysis 

 of all the structural characters that can be made out, there remains but a 

 single palpable distinction: the Cowles hill specimens are uniformly smaller. 

 This may be a difference of significance in consideration of the great time 

 interval in their appearance, but with a reservation in favor of this point only, 

 I unhesitatingly refer the tonus under consideration to that specific type. 



The reappearance of this species is the more interesting as in the Ithaca 

 meridian it is best developed at a well-defined horizon near the base of the 

 entire Portage sediment, where it is highly abundant, but strongly localized. 

 Professor W illiams has recorded its brief recurrence in this meridian after 



