BRITISH FOSSILS. 9 



nation of a specimen of any such structure, but that it is deduced from 

 the character of the markings upon the surface of the phragmocone 

 originally described by Volte. In point of fact I/Orbigny made no 

 real addition to the discoveries and conclusions of the latter excellent 

 observer. 



Quenstedt (Die Cephalopoden. p. 389) agrees with Yoltz in the descrip- 

 tion of the lineations of the sheath of the phragmocone, bat declines to 

 deduce thence the existence of a pen. Making no distinction between 

 the views of Bnckland and those of Agassiz, and continuing to deny 

 the existence of evidence justifying the connexion of such pens as those 

 of Loliffo Bollenfit. with Bclemmtrj. he falls into the error of doubt- 

 ing Buckland"s identification of the nacreous pro-ostraca^ &c. of Lyme 

 Regis with Belemnites ; and, after a critical examination of Btlem- 

 nilft semismlcatu*, he is disposed to admit, at most, ~ that the shell 

 ~ of the Belemnite alveolus (= phragmocone) did not end superiorly 

 ** by a circular lip, but in a unilateral parabolic process, which can by 

 '* no means be safely compared to a true Loligo pen." 



M. Duval Jouve (" Belemnites des Terrains Cretaces InfenemW 

 1841), observed no pro-osrracum attached to any of the specimens he 

 studied. 



In describing the specimens upon which he founded the genus 

 Bclemmolfutkis, in the " Proceedings of the Geological Society "for 

 1842, Mr. Channing Pearce indicated the existence of a " sepiostairc " 

 in that genus, in addition to the phragmocone and guard. 



Professor Owen, in his memoir " On the Belemnites " (Phil. Trans. 

 1844), having mistaken BelemnoteiUkis for Btleimnitet. describes the 

 rudimentary rostrum of the former as the conotheca of the hitter : with 

 regard to the existence of a pro-ostracmn in Belemnites generally, he 

 follows Dr. Bnckland (Lc., p. 66). 



In 1848 Dr. Mantell (Observations on Beleniniie-. &c~ Philosophical 

 Transactions) gave a more complete account of the pro-ostracum of a 

 Belemnite ( Belemmiltx 'aifeittiatits) than had previously appeared. In 

 describing the specimen figured in his Plate XV., fig. 3, he writes, 



** This fossil comprises the following parts : 1. The capsule or 

 pfriotfraeum. This external investment (c 1 . e 1 . e 1 ), which consists of 

 a thin, shelly, or corneo-calcareons integument that closely embraces 

 the guard, and, gradually enlarging upwards, finally surrounds the 

 peristome of the phragmocone. constituting; the thin horny laminated 

 sheath or receptacle (<% r), has been described by all previous' 

 observers as an extension of what they termed the sheath, or capsule ; 

 within this receptacle the ink-bag and other viscera were probably 

 contained * * ~ * * * 



The phragmocoue enlarges upwards, and anteriorly to the siphonated 

 part constitutes a large chamber, from the margin of which are pro- 

 duced two or more long, upright, shelly or calcareous processes, as 

 shown in PL XV., Fig. 3 ft, ft 1 ." 



In a subsequent memoir* Dr. Mantell shows that there were but two 

 of these processes, that they were situated nearer the dorsal than the 

 ventral aspect of the phragmocone, and that they were continued 

 downwards into * nacreous bands or plates, finely striated ** upon the 

 outer surface of the chambered cone. 



A- I have already indicated, Quensiedt (Die Cephalopoden, 1849) 

 discusses the question of the presence or absence of a pen in the 

 Belemnites at great length, without arriving at any decided result ; 



* On the traettnv of the Briemnhe sad Brteanratevtfcis. Pbikwophkal Tbansae- 



