1908.] NATURAL SCIENCES OF PHILADELPHIA. 49 



Length 26, diam. 16, length of aperture 18 mm. 

 " 25 " 13.5 '' " 17.5 " 



This size is not often reached . In the middle West a length of 20 mm, 

 is near the maximum, and the size of some individuals which seem to 

 be adult is not greater than the largest of the typical form of S. ovalis. 



Fio;. 4. — Succinea ovalis optima. Xat. size. 



This large race is what has commonly been called S. obliqua Say, but 

 the true obliqua is merely the longer phase of typical ovalis, and the 

 name is not fairly applicable to the form above described. I have 

 not examined the living animal of this race. 



I picked up a single bleached specimen of S. o. optima on the beach at 

 Galveston, Texas, in 1886. It had probably floated there, as I do not 

 think it exists in the Austroriparian zone. 

 Sucoinea ovalis ohittenangoensis n. subsi.. Pl. VII, figs. 1 to 8. 



The shell is yellow or pinkish-yellow, much lengthened, with a longer 

 spire than any other race of S. ovalis; suture deep; whorls 3^, the last 

 rather flattened above, not so convex there as in S. ovalis or S. o. 

 optima. Aperture very oblique, relatively small. 



Length 22.5 diam. 11.5, length of aperture 14 mm. (No. 90,087). 



" 23.3 " 11.3 " '' 14 " (No. 90,081). 



" 21 " 11.3 " '' 13 " (No. 90,079). 



'' 19 " 10.5 " " 12 " (No. 90,083). 



Cotypes from a sloping weed-covered talus near the foot of Chitten- 

 ango Falls, Madison Co., N. Y., No. 90,087, 90,081 and 90,079, A. N. 8'. 

 P., collected August 27, 1905, by Messrs. Henderson, Walker, Clapp and 

 Pilsbry. 



A very large series was taken, associated with a few S. ovalis, from 

 which they are easily separated by the characters given above. I have 

 seen this form from nowhere else. The locality is on the Onondaga 

 limestone (coniferous). 

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