2l6 NEW YORK STATE MUSEUM 



ter shale and Lockport limestone at Lockport (Hall), and probably 

 also at Niagara. 



Orthoceras xnedullare Hall (i860. Gcol. sur. Wis. Rcp't prog. p. 4) 

 Distinguishing characters. Cylindric, gradually tapering form; 

 septa distant nearly half the diameter; large siphuncle, slightly ex- 

 panded between septa; strong sharp subequal longitudinal striae, 

 with often alternating finer striae ; smooth cast. 



Found in the Clinton limestone lenses in the Rome, Watertown 



and Ogdensburg railroad section 

 above Lewiston. Rare. The species 

 r:;7 ^ is normally a western one. 



l'" Genus cyrtoceras Goldfuss 



; [Ety. : y.upros, curved; xipaq, horn] 



f ; ; ( x 837. De la Beche, Handb. d. 



/- " w Geogn. bearb. von v. Dechcn. p. 536) 



;V ,-~> Shell conic and gently curved, with 



.;;'. / a depressed elliptic to trigonal cross- 



£. / section, the aperture in old shells con- 



„" V tracted to a T-shaped opening; si- 



phuncle large, eccentric. 



^^_ ■/ Cyrtoceras subcancellatum Hall 



(Fig. 148). Cyrtoceras (?) 



Fig. 148 Cyrtoceras subcancellatum cance llatum Hall (1852. Pal. 



N. Y. 2:290, pi. 61) 



Distinguishing characters. Arcuate; transversely oval section; 

 transversely striated surface, and faint longitudinal striae; siphuncle 

 submarginal. 



Found in the " limestone below the cliff at Niagara Falls " (Hall). 



Genus gomphoceras Sowerby 



[Ety.: yuofitpo?, a pin, bolt, or club; -/Jpa ? , a horn] 



(1839. Murchison. Silurian system, p. 620) 



Shell straight or curved, pear-shaped, greatest diameter in front 

 of the middle; cross-section circular; mouth contracted, opening by 

 a T-shaped aperture ; siphuncle central or eccentric, subcylindric or 

 expanding between the septa (moniliform). 



