48 



sinuous on the margins. Superior lateral lobe about the 

 size of the dorsal saddle, palmately divided at the extremity 

 into three large irregular branches, which have three or 

 four sharp digitations at the ends ; above these terminal di- 

 visions the sides of the lobe are ornamented by two or three 

 irregular alternating, sinuate lateral branches. Lateral 

 saddle smaller than the superior lateral lobe, having on each 

 side below two or three irregular alternating lateral divi- 

 sions, and at the extremity two unequal terminal branches, 

 each of which is again subdivided into two parts, which are 

 bifid or trifid at the ends. The inferior lateral and first 

 auxiliary lobes are much smaller than the superior, but 

 very similar in their mode of branching ; while the suc- 

 ceeding lobes are very small, oblique, and nearly simple or 

 only having small sinuosities along their margins. 



The specimen from which the foregoing description was 

 made out measures in its greater diameter 2'28 inches, and 

 in its smaller *90 inch. As it consists of the inner whorls 

 of the shell, it is probable the outer volutions of adult indi- 

 viduals may have varied somewhat in their external orna- 

 ments, as well as in the details of their internal structure. 



Externally it is nearer A. mutabilis of Sowerby (Min. Con. 

 vol. 4, p. 145, pi. 405), than any species I have seen figured 

 in foreign works, but in its internal structure it must have 

 varied materally from that species, as Mr. Sowerby mentions 

 in his description of A. Kcenigii, which is only a variety of 

 A. mutabilis, that the septa are not deeply sinuate. 



I have named this species in honor of Dr. J. S. Newberry, 

 Geologist of Lieut. Williamson's north California and 

 Oregon exploring expedition. 



Baculites ovatus ? (Say). — Along with the other speci- 

 mens in this collection, I find two fragments of a Baculite 

 having exactly the form and general characters of B. ovatus 

 (Say). In some of the minute details of its septa it presents 

 slight differences from authentic specimens of Say's species, 



