INVERTEBRATE PALAEONTOLOGY. 501 



Cretaceous Nautili of India (Palseont. Indica, I, 29). Yet it is a little sin- 

 gular that they both retain the name N. elegans for d'Orbigny's type, and 

 cite d'Orbigny as the author of the name, although he merely referred it to 

 Sowerby's species published long before. Blanford protests against this 

 application of Sowerby's name to forms like that.figured by d'Orbigny, but 

 still follows Pictet in it. If N. elegans, d'Orbigny, is specifically distinct 

 from the previously-published JY. elegans, Sowerby (which seems very prob- 

 able), of course d'Orbigny's shell will have to receive some other name, as 

 two species of the same genus cannot retain the same name. 



Dr. Shumard, some years back, described a shell of this type in the 

 Transactions of the Saint Louis Academy, vol. I, page 590, from the Creta- 

 ceous rocks of Texas As he mentioned, however, that its siphuncle is situ- 

 ated between the middle and the ventral (inner) sides of the septa, it must 

 differ from that here under consideration, and agree more nearly with N. 

 pseudo-elegans, d'Orbigny, which, with this exception, is very closely allied to 

 JV. elegans, Sowerby, as well as to that figured by d'Orbigny under Sowerby's 

 name. 



Locality and position. — Chippewa Point, Montana ; from the Fort Ben- 

 ton group of the Upper Missouri Cretaceous series. 



DIBRANCHIATA. 



BELEMNITID^E. 



Genus BELEMNITELLA, d'Orbigny. 



Synon. — Belemnites (part), Lamarck (1799) ; and of mauy later authors, but not as restricted by d'Or- 

 bigny and others. 

 Belemnitella, d'Orbigny (1840), Pale'ont. Fi\, Terr. Cre't., I, 59 (as a subgenus under Belemnites) ; 

 and (1842) Diet. Univ. d. Sci. Nat., II, 531 ; also (1845) Geol. Russ., II, Pale'ont., 489 ; 

 and (1850) Prodr. Pale'ont., II, "211 (as a distinct genus). — Agassiz (1840), Germ. Transl. 

 Sowerby's Min. Conch., 633. — Woodward (1850), Man. Moll., 74. — Meek and Hayden 

 (1856), Proceed. Acad. Nat. Sci. Philad., VIII, 70 ; and (1860) ib., XII, 419.— Chenu 

 (1859), Man. Conch., I, 50. — Biukhorst (1861), Monogr. Gasterop. et Cephalop. Craie 

 Sup. de Limbourg, I. — Favre (1869), Descrip. des Moll. Foss. de la Craie des Environs 

 de Lemberg, 1. — Meek (1864), Smithsonian Check-List N. Am. Cret. Fossils, 26.— 

 Koemer (1870), Geol. von Oberschlesien, 357 ; and of many others. 



Ettjm. — (tifa/ivov, a dart. 



Type.. — Belemnites paxillosus, Lam. (= B. mucronatns, Schloth.). 



Guard cylindrical or more or less clavate, provided with a deep conical 

 cavity in the anterior end for the reception of the phrogmacone, and usually 

 more or less pointed behind; wall of the conical cavity divided by an open, 



