BRITISH FOSSFLS. 



occasionally found in contact with traces of isolated alveoli of Belem- 

 nites ; they are more ^frequently surrounded only by a thin plate of 

 brilliant nacre." 



In his statement of the component parts of a Belemnite (L c., p. 372), 

 Dr. Bnckland yery clearly demies the characters of the part which he 

 had discovered ; it is, says he, ** a conical, thin, horny sheath or cup, 

 commencing from the base of the hollow cone of the fibro-calcareoui 

 " sheath, and enlarging rapidly as it extends outwards to a considerable 

 " distance. PI. 44', fig. 7 b, e, e', e". This horny cup forms the 

 ** anterior chamber of the Belemnite, and contained the ink-bag (e) and 

 ~ tome other viscera." 



In Dr. Buckland's restoration of the " Beleinnosepia," PL 44' fig. 1, 

 the cup in question, or pro-ostracum, e, e t is made to extend nearly to 

 the anterior end of the mantle of the animal. 



In the preceding year (1835) Professor Agassiz communicated a 

 short note, a Ueber Belemniten," to Leonhard and Bronn's " Jahrbuch." 

 in which he states that " he has made out with certainty that the so- 

 called Onychotenthif prisca with the ink-bags, as they are figured by 

 Van Zieten (as Loligo, Tab. XXV'.), are nothing but the anterior pro- 

 longation of a Belemnite, and, indeed, of B. oralis, a? is shown by a 

 perfect specimen from the Lias of Lyme Kegis, in Miss E. Philpotts' 

 collection. ** The Belemnites have, therefore, the plate of Onychoteu- 

 " tki&, as a prolongation of the alveolus, and, internally, the ink-sac of 

 - Sepia." 



-hall find reason to believe, however, that what Von Zieten 

 figures in the plate referred to are pens of Loligidte. And it must be 

 particularly observed that Agassiz and Buckland. though apparently in 

 agreement, are not really so. Dr. Bnckland neither assents to the 

 proposition that the pens figured by Von Zieten belong to Belemnites, 

 nor does he agree with Professor Agassiz' opinion that Miss Philpotts' 

 specimens exhibit traces of such a pen. 



In the paper entitled " Bemerknngen uber das genus Belemnosepia 

 ** und uber den fossilen Dinten-sack in den vorderen Kegel der 

 " Belenmiten." in fact, Buckland speaks of Von Zieten's specimens a? 

 " species of Loligo " (p. 39. note), and in the Bridgewater Treatise, 

 p. 308, when treating of the pens and ink-bags of " Loligo" in the 

 English Lias, he says, 



" We learn from a recent German publication (Zieten's Versteine- 

 rungen Wurtembergs, Stuttgart, 1832, PI. 25 acd PL 37), that similar 

 remains of pens and ink-bags are of frequent occurrence in the Lias 

 shales of Aalen and Boll." 



Taking for granted the correctness of Professor Agassiz' interpreta- 

 tion of the pen called " OnycJioteuthis prisca," as the pro-ostracmn of 

 Belemnites oralis, .M. Voltz contributed much towards the acceptance 

 of that interpretation by essaying to prove (Ueber Qnychotevthis pritca 

 von Munster ; Leonhard und Bronns Jahrbuch, 1836, p. 323), that the 

 arrangement of the lines of growth in the former corresponds with that 

 of certain striations upon the couotheca of Belemnites to which he had 

 drawn particular attention in his " Obeervationes sur les Belemnite? " 

 (1830). These are two systems of very remarkable striae visible on 

 the outer surface of the lamellated test composing the conotheca : 

 " the one kind are straight and set out from the apex, they are 

 " analogous to the longitudinal striae of all univalve and bivalve shell?; 

 " and the others are more or less transverse." The first set are 

 usually well seen only in the ventral or internal face. " Commonly, 

 " the external lamina of the conotheca shows them more distinctly 

 " than the internal lamina?, whilst the other striae are seen equally 



