278 Mr. Parkinson on Hippurltes. 



M. Lamarck concludes his description of this fossil by saying, 

 that the last chamber is closed by an operculum ; a circumstance which 

 M. Picot de la Peyrouse had supposed that he had frequently ob- 

 served, whilst examining the numerous specimens which he had 

 found on the Pyrenees. The existence of this operculum is however 

 positively denied by M. Denys de Montfort, who considers this 

 supposed operculum as only one of the septa bearing the impression 

 of the posterior part of the animal. Two specimens* coritalii 

 sections of these fossils, towards their superior termination ; and 

 shew, perhaps, the inner side of this last septum or supposed oper- 

 culum ; but do not appear to yield any marks which may assist 

 in determining on the real nature and office of these parts. 



M. Picot dc la Peyrouse, besides finding several of these bodies 

 of a conical form, whose length did not exceed their diameter, 

 found others of a cylindrical form, some of which were a foot and 

 a half in length, though not more than an inch in diameter ; and 

 of course nearly as large at one end as at the other. The regular 

 manner in which he found these fossils arranged by the side of each 

 other led him to describe them as resembling the pipes of an organ. 

 M. Denys de Montfort has thought proper to place the fossils of 

 this description under a new and distinct genus, which he names 

 Batolites organisans^ ( Le batolite tuyau d'Orge.) The hippurite he 

 remarks is constantly bowed and short, and possesses a very thick 

 shell ; whilst the batolite on the contrary is straight and long, and 

 has a very thin shell. 



In another specimen f a section of one of these fossils is seen 

 possessing a much greater degree of curvature than that which is 

 seen in No. I. which indeed departs but little from the straight 

 line. These tv;o fossils may be regarded as intermediate in their 



* No. 2 & 4. t No. 5. 



