8 POSSIL MOLLUSCA OP THE CHALK. 



impressed line runs down the back of the alveolar cavity. Vascular impressions apparently 

 resembling those of B. mucronata are faintly marked and frequently obliterated. 



This Belemnite, M^hich was well distinguished by the earlier writers on the subject, has 

 been confounded by all later authors with B. mucronata, from which it is distinguished 

 externally, by its less cyhndrical form, and fainter vascular impressions ; and internally, 

 by the central position, and more circular section of the alveolus. 



Breyn, one of the earhest writers who made an approach towards the true nature of 

 Belemnites, distinguished the present species from B. mucronata without naming either, 

 and has given good figures of both, as Species 1 and 2. He was followed by Schlotheim, 

 who, referring to Breyn's figures, names his 1st species B. mucronatus, and his 2d species 

 B. lanceolatus, which names we must adopt, on the principle of priority ; an unlucky re- 

 mark of Schlotheim that, perhaps, Montfort's HibolitJms hastatus might prove a variety of 

 his B. lanceolatus, has led both D'Orbigny and Bronn to throw aside Schlotheim's name 

 B. lanceolatus, as a synonym of B. hastatus ; the slightest reference to Breyn would have 

 saved them from this error, as that author's 2d species belongs clearly to the Genus 

 Belemnitella, the slit down the front of the alveolar cavity being well shown in the 

 figures, and clearly described in the text. 



Miller was probably aware of the difference between the two species, since finding this 

 one figured by Blainville as B. mucronaius, he gave to the original B. mucronatus the new 

 name of B. electrinus. Woodward living in Norfolk, where the two species are abundant, 

 was well acquainted with both, and distinguishes them clearly in his Catalogue, as 

 B. mucronatus tapering off to a point, and B. electrinus obtuse, with a mammillated 

 point. 



Sowerby, Min. Con., t. 600, threw the two species together, figuring them both under 



the name of B. mucronatus, and the same is done by M. D'Orbigny, in the second volume 



of the ' Geol. of Russia, where they are well figured as Belemnitella mucronata, variete 



fusiforme and variete r en flee ; but in the ' Paleontologie Fran^aise' we have only the true 



B. mucronata, well figured and described, without any allusion to the other form. 



3. Belemnitella quadrata, Defrance, Sp. Plate I, figs. 7 — 11. 



Belemnites quadratus, Blainville. Belemnites, t. i, fig. 9. 



— GRANULATUS, Sowerby. Min. Conch., t. 600, figs. 3 and 5. 



Belemnon pustulatum, Kcenig. Icones Foss. Sect., No. 216. 

 Belemnitella quadrata, D'Orbigny. Paleont. Fran?. Terr. Cret., t. vi, figs. 5 — 10. 



B. testa subcylindricd,granulatd ; apice obtusiusculo mucronato ; apertnird suhquadratd : 

 alveolo in/erne rotundato conico, superne expanso subquadrato. 



Shell nearly cylindrical, rounded towards the apex, which ends in a distinct point ; 

 alveolus wide, and four-sided above ; round and conical below, with a short sht on the 

 anterior side, which reaches into the rounded part of the cavity; surface almost entirely 



