2 THE FAUNA OE THE NEOOOMIAN. 



usually expanded into a short wing ; the amho is thick, generally prominent and in- 

 curved, and, if there are no marks of fixing, slightly reversed at the apex ; a more 

 or less distinct furrow runs down the posterior side; ligamental pit triangular and 

 long. Surface somewhat foliaoeous, otherwise smooth. Marks of fixing usually 

 rathe^ large. 



Left valve small, irregularly oval, flat or lightly concave, exceedingly thick at 

 the umhonal region, hut quickly becoming thinner in ventro-posterior direction ; 

 ligamental pit long and triangular ; surface lamellous, covered with numerous strong 

 striae of growth. 



Locality and strati graphical position.— Sexnbsiv Pass, and range north of 

 Ghora Dund ; belemnite shales. 



IBemarka.— -This nice little species is easily recognized by its peculiar shape ; in 

 typical specimens it appears as above described, but it varies a good deal in shape ; 

 the umbo of the left valve becomes less prominent and the right valve is frequently 

 much thinner, but still the general character remains the same. 



II.— CEPHALOPODA. 

 Order: BELEMNOIDEA. 

 A. PHRAGMOPHORA. 



Pamily: BELEMNITIDM. 



Subfamily : BELEMNITIN^. 



Genus: BELEMNITES, List. 



1 Section: Notocoeli. 



Group: DILATATI. 



Belemnites (Duvalia) dilatatus, Blainville, plate II, figs. 1-lJ, 2-25, 3-3&, 



4-46, 5-56, 6-66, 7-76. 



1827. Belemnites dilatatus, BlainTiUe, M^moire sui- les Bfiletnn., page 99, pi. 3, fig. 13 ; pi. 3, fig. 18. ( For 

 synonyms see Duval-Jonve, Belemnites, page 54.) 



The guard varies considerably in shape ; in fact there are hardly two specimens 

 which are exactly alike ; its general shape is elongated, but always strongly com- 

 pressed laterally ; transversely elliptical, rounded or acuminate at the posterior end, 

 but always with a short point. In some instances it is posteriorly expanded, taper- 

 ing towards the anterior end, while in others the posterior region is narrow, the an- 

 terior broad. The sides are generally flattened, but sometimes they are slightly 

 tumid. The ventral side is rounded, narrow, undulating or straight ; the dorsal side 

 broadly rounded and convex. Ventral canal narrow and comparatively short. 

 Sides marked by a double, somewhat indistinct dorso-lateral furrow. Transverse 

 sections varying, but generally elliptical. Alveolar cavity not observed, 



