NO. 1192. TRENTON FAUNA OF BAFFIN LAND— SCRUCHEBT. 169 



Class OEFHi^LOI^Oi:)^. 



Order TETRABRANCHIATA. 

 Family ENDOCERATIDiE. 



CAMEROCERAS PROTEIFORME (Hallj. 

 Cameroceras proteAforme Clarke, Geol. Minn., Ill, Pt. 2, 1897, p. 777, pis. 



XLVIII-LI, LIII. 



Of this common species there is one small but well-preserved frag- 

 ment showing- the submarginal siphon. In a length of 2 inches, there 

 are seven chambers and eight septa. 



Collector.— 3. IS. Oarpender. Gat. No. 28191, U.S.N.M. 



Family ORTHOCERATID^. 



ORTHOCERAS OLORUS Hall, var. BAFFINENSIS. new variety. 

 (Plate XII, figs. 19-22.) 



Orthoceras vertebrale Hall, Pal. N. Y., I, 1847, p. 201, pi. XLiii, figs. 5-5c (not 



Schlotheim, 1820). 

 Orthoceras olorus Hall, Miller's Amer. Pal. Foss., 1st ed., 1877, p. 245. 



The Arctic examples of this form, of which there are tbree, do not 

 appear to attain the large size of the New York specimens. Hall 

 describes the species with " strong longitudinal strise," while the Arctic 

 specimens have very fine equidistant lines, between each of which are 

 from 3 to 6 exceedingly delicate ones. This difference in the ornamen- 

 tation, together with the smaller size, is regarded of sufficient impor- 

 tance for varietal distinction. There is no other American Lower Silurian 

 annulated species with which it can be compared. 



Collectors.— J. N. Carpender and A. H. White. Oat. No. 28192, 

 U.S.N.M. 



ORTHOCERAS BILINEATUM Hall. 



Orthoceras hilineatum Clarke, Geol. Minn., Ill, Pt. 2, 1897, p. 786, pi. XLVil, 

 figs. 20, 21; pi. Liv, figs. 6, 7. 



Of this species there is one small specimen annulated throughout. 

 The characteristic, regularly alternating, larger and smaller lines of 

 ornamentation are preserved. 



Collector.— A. H. White. Cat. No. 28193, U.S.N.M. 



ORTHOCERAS PORTERI, new species. 



(Plate XII, figs. 23-25.) 



This annulated species of Orthoceras appears to be related to 0. hilin- 

 eatum. The apical angle in both is about the same, but in 0. porteri 

 the annulations and septa are farther apart, the siphuncle is more 

 eccentric, and the ornamentation is entirely different. The longitudinal 

 lines are double throughout, and consist of prominent primary ones, 



