CEPHALOPODA. 2G3 



proper, in their eastern and western extensions. This inference regarding 

 the extensive distribution of the species is based upon very imperfect material, 

 and may be in part due to the obscurity of the specimens from the upper 

 limestones, which do not admit of specific distinction. 



Formations and localities. In the Schoharie grit at Schoharie, and at various 

 localities in the Helderberg range ; in the Upper Helderberg limestone at 

 Caledonia, Livingston county; Clarence Hollow, Erie county; and at Onondaga 

 Valley, Onondaga county, N. Y. It has also been identified among collections 

 from the limestones at Columbus and Dublin, Ohio. 



Orthoceras mclticinctum. 



PLATE XLIII, FIGS. 1-3. 



Orthncercut multicinctum. Hall. Descriptions of )Ne\v Species of Fossils, etc., p. 48. 1861. 

 " " " Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 76. 1862. 



" " " Illustrations of Devonian Fossils : Cephalopoda. Explanation of plale 



43, figs. 1-3. 1876. 

 Not " " Wikchell. Proceedings of the Academy of Natural Sciences, Phila. 1862. 



Shell straight, regularly enlarging. Transverse section circular. The apical 

 angle, measured in a small fragment from near the apex, is 9°. The larger 

 specimens do not admit of this measurement, as they are much compressed 

 or weathered ; but they show that the tube was more rapidly expanding 

 than in 0. Thoas. Initial point unknown. 



Chamber of habitation well developed, slightly ventricose, gradually con- 

 tracting toward the aperture from a point near the middle. Air-chambers 

 numerous, regular, having a depth of about three mm. where the tube has a 

 diameter of twenty mm. 



Septa thin, moderately concave. Sutures straight and horizontal. 



Siphuncle not observed. 



Some traces of the surface ornaments, consisting of regular, longitudinal 

 stria), are shown upon the casts. The shell is ornamented by numerous, 

 rounded annulations, of which there are four, eight and fifteen in the space 

 of twelve mm., as shown by measurements taken from two specimens. In 

 specimens not compressed, the annulations are straight, and not oblique on 

 any part of the tube. 



