206 Annals of the Carnegie Museum. 



Trochonema dispar Raymond. 



(Plate LIIT, figures 7, 8.) 

 Trochonema dispar Raymond, 1905, American Journal of Science, 



Series 4, Vol. XX, p. 378. 



This species is rather rare and is closely related to Trochonema 

 umbilicatum Hall. It differs from that species principally in the 

 greater convexity of the under surface of the whorls and the less pro- 

 nounced angularity of the body whorl. 



Description. 



Shell rather large, consisting of three whorls with depressed spire 

 and very large body whorl. The suture is very deep and the whorls 

 are almost free. The body whorl has a flat revolving band on the 

 outer side. The top is flat and sloping and the lower side strongly 

 convex. The surface markings are not shown. The umbilicus is 

 large in the cast but rather small in testiferous specimens. 



Locality. — Fairly common in the Chazy at the south end of Valcour 

 Island. It is rare elsewhere on Valcour Island and at Chazy, New 

 York. 



The type is in the collection of the Carnegie Museum. 



Trochonema rectangulare Raymond. 



(Plate LIII, figures ii, 12.) 

 Lophospira rectangularis Raymond, 1905, American Journal of 



Science, Series 4, Vol. XX, p. 377. 



Although no surface markings are present in any of the specimens 

 of this species, a fancied resemblance to Lophospira perangnlata (Hall) 

 led the writer, in the article referred to above, to describe this species 

 under the generic name Lophospira. This species somewhat resembles 

 Trochonema robbinsi Ulrich and Scofield, and Trochonema niota Hall, 

 but can readily be distinguished from both those species by its fewer 

 and more rapidly expanding whorls and the smaller umbilicus. The 

 figures show that it is not similar to any of the other species of 

 Trochonema in the Chazy. 



Description. 



Shell fairly large, with five volutions. Body whorl very large, spire 

 small. The last three whorls have the sides parallel to the axis of the 

 shell. Body whorl with two keels, separated by a flat band, the width 



