412 Proceedings of the Ohio State Academy of Science. 



sides of the volutions are marked by a series of nodes of con- 

 siderable strength and size, arranged at regularly increasing dis- 

 tances, and occurring, as nearly as can be determined from the 

 example on hand, at about every second septum. The nodes are 

 situated on the crest of the side, and are obtusely rounded and 

 prominent. Septa moderately distant and but slightly bent down- 

 ward on the dorsum [venter?]. On a specimen measuring about 

 three inches in its greatest diameter, the whole of which is 

 septate, they are arranged at about one-third of an inch apart ; 

 near the outer extremity of the last volution. Siphuncle not 

 observed, and the depth of the septa not ascertained. The sur- 

 face of a portion of the specimen bears marks of a series of 

 strong varices of growth, which have crossed the dorsum 

 [venter?] and show a strong retral sinus or notch in the margin 

 of the lip at this point. The varices are seen in the inner 

 portion of the last volution and appear to have been arranged 

 at distances nearly corresponding to the septa at the same 

 place. No other markings of the surface are retained [Whit- 

 field, 1895]." 



As Whitfield points out, this species closely resembles the 

 illustrations and description of the one originally named Nautilus 

 forhesianus by McChesney. Apparently the only difference is 

 the location of the line of lateral nodes. In the species specta- 

 bilis the line is so located that the greater portion of the volution 

 lies on the peripheral side while in forbesianns the larger part 

 occurs on the inner side. Why two species so nearly alike that 

 they can scarcely be separated specifically, should subsequently 

 be referred to two distinct genera (Endolobus spectabilis and 

 Teninocheilus forbesianus) is rather hard to understand. 



Horison and locality. — Maxville limestone. 

 Unknown zone: Rushville (Andrew's collection). 



