406 UNITED STATES GEOLOGICAL SURVEY OF TEE TERRITORIES. 



Baculites anccps, var. o b t u s u s . 



Baculites vertebralis, Defrance (1810), Diet. Sci. Nat. Suppl. Ill, 1C8 (and of some others, not of Lamarck, 

 1801). 



Baculites dissimilis, Desmarest (1817), Jour. Phys., LXXXV, 48, pi. ii, figs. 4-6.— Dellaau (1825), Mon. Amm. 

 et Goniat., 155. 



Baculites anceps, Lamarck (1822), An. sans Vert., II, 648.— D'Orbiguy (1825), Tab. des Ceph., 75 ; and (1840), 

 Paleont. Fr. Terr. Cr<5t., I, 565, pi. 139, tigs. 1-7.— Deshayes (1830), Eccyc. Mdth, XII, 

 108 ; and (1831) Coq. Car., 224, pi. 6, fig. 2.— Bronn (1837), Leth. Geog., 732, tab. 33, fig. 

 5.— Heisinger (1837), Leth. Suec, 31, tab. v, fig. 2.— Eoemer (1852), Kreid. von Texas, 

 36, taf. II, fig. 3, a, b, c, (d, <•,/, g ?)— Binkhorst (1861), Monogr. Gast. et des Ceph. Craie 

 Sup. du Limbourg, 42, pi. v, figs. 3, a, b, c. — Gabb (1861), Proceed. Acad. Nat. Sci. 

 Philad.,XII,395 ; and of numerous others. 



Baculites Faujasi (part), De Haan (1825), Monogr. Amm. et Goniat., 155 ; and of some others. 



Baculites carinatus, Morton (1834), Synop. Org. Rem. Cret. Form. U. S., 44, pi. xiii, fig. 1. 



1 Baculites Tippaensis, Conrad (1858), Jour. Acad. Nat. Sci. Philad., Ill, 334, pi. 35, fig. 27. 



Fig. 57. 



Fig. 58. 



V 



4 





> v 



Baculites anccps, var. obtusus. 



Fig. 57. A side-view of non-septate part, natural size. 



Fig. 58. A septum magnified to about twice and a half the natural diameter. 



Fig. 59. An antisiphoual view of a septate fragment, showing this part of the 



shell to be also distinctly undulated. 

 Fig. CO. A section of last, showing its obtusely-rounded siphonal margin. 



Shell small, very slender, and very gradually tapering ; 

 section ovate, being rounded or slightly flattened on the 

 antisiphoual side, and more narrowly rounded, or some- 

 times obtusely subangular, and often crossed by scarcely perceptible little 

 ridges on the siphonal margin ; lateral surfaces ornamented by strong, regu- 

 lar, arcuate costse, or undulations, that sometimes become nearly obsolete 

 toward the smaller extremity; septa moderately distant; siphonal lobe wider 

 than long, with two widely-separated, diverging, digitate, terminal branches, 

 and lateral digitations ; first lateral sinus slightly longer, and distinctly nar- 

 rower than the siphonal lone, and provided with two short, subequal, sinuous 

 and digitate terminal divisions, with one much smaller, slightly sinuous, 

 lateral branch on either side near the terminal ones, and a few other smaller 

 lateral digitations ; first lateral lobe of nearly the same size and form as the 

 first lateral sinus, excepting that its short principal lateral branches are 

 broader; second lateral sinus slightly larger, but in other respects agreeing 



