Orthoc. 



556 



Wkitf*eld. Buli:AM,jr:2. 



Orthoceras pressum, Rogers, 1858. — Bigsby, Thes. Silur. 

 Trenton. Quoted in Report T, page 55. — II c, 

 Orthoceras primigenium, Vanuxem. Geol. 3rd. Dist N, 



Y. 1842, page 

 36, fig. 2, 4 

 — Emm 

 Geol. 2d Dist. 

 page 179, fig. 

 53,4. Cdlcif- 

 erous sand- 

 stone. II a. — Hall, Pal. N. 

 Y., Vol. 1, p. 13, plate 3, 

 figs. 11 and 11 «.— Whit- 

 Van . i- \. '-■™'i^'-«»iii»'M!Hl£ fleld, Bulletin Amer. Mu- 

 seum Nat. Hist. N. Y. Vol. 2, No. 2, page 56, plate 10, fig. 1, 

 long section showing septa in lower half; syphon apparently- 

 very small and subcentral. Beekmantown, N. Y\Calc, II a. 

 Orthoceras profundum, Hall. 15th Annual Report, 1862, 



page 7 6, 

 plate 7, fi 

 8, el 



mark e d 

 engthwise 

 by sharp 

 ridges, one- 

 //<^/f. js/rTiTTTFlJST'^^ tenth of an 



inch apart; and ringed (annulated) by sharp rather distinct 

 stri^, giving the long ridges a wavy look ; also often finer striae 

 of growth ; differs from 0. imbrieatum of the Niagara in show- 

 ing no intermediate finer longitudinal striae; and from O.vir- 

 gatum in more regular arrangement of both long and Cross 

 lines. In two individuals of 1^ inch diameter the preserved 

 portion of the outer chamber is 6 inches long. Upper Helder- 

 lerg limestone at Waterville, N. Y. — VIII a. 



Orthoceras punctostriatum, Hall. Dawson's Acadian 

 Y-v\. 212 Gleology, 1868, page 605, fig. 212 ; section circu- 



lar, siphuncle central; surface very finely 

 striated with unequal wavy striae, between which 

 are oblong indentations, often running into each 

 other. A shell remarkable for its extremely slight 





