348 Viscount cI'Archiac and M. de Verneuil's 



very slightly concave, placed two millimetres from each other, and not continuing quite so far as to 



the part where the shell acquires its greatest breadth. The remainder, as far as to the aperture, 



forms the last chamber. Siphon very small, round, and marginal, increasing its distance from the 



margin as it rises to the last septum, where it is at a distance of four millimetres. 



While we preserve to this species the name of subpyriformis, we must remark that the chambers are 



only half the height of those given in the otherwise incomplete figure of Count Miinster. The form, 



however, appears to be very variable ; and the chambered part of some very inflated varieties has 



the aspect of the Apiocrinite of the Bradford clay. Among these specimens not one has shown us the 



folds which according to Count Miinster accompany the outer margin of the upper septum and which 



give it the appearance of the joint of an Jilquisetum, but a very distinct notch is seen in the interior 



immediately above the suture of the last septum. We have observed folds similar to those in question 



upon individuals from the limestone of the Eifel, and it might be thought, that they had some relation to 



the manner in which the animal was affixed in this last chamber of its shell. 



The disposition of the aperture in the present species appears to be common to all those for which the 



name of Gomphoceratites has been proposed, as well as to the Phragmoceratites. The O. subpyriformis is 



distinguished from O. pyriformis (Sow. Sil. Syst., PI. VIII. f. 19, 20) in the position of its siphon and in the 



form of its aperture. This shell is naturally placed between the Orthoceratites and the Phragmoceratites. 



Paffrath. It is doubtful if the shell of the Eifel and Fichtelgebirge be identical with this. 



Siphon of Orthoceratites ? Tab. nost., XXX. f. 3,3 a. 



We have given a representation of this which appears to us to be a cast of the annulated siphon of a 

 very large species of Orthoceratite, in which case it would be placed near to the Conotubularice.ot Troost. 

 In it may be seen contiguous rings divided by vertical grooves into a great number of rounded pearl- 

 like tubercles. The section of this body shows nothing in the interior but limestone similar to the rock 

 in which it occurs, and it is without any trace of siphonal cavity. 



Paffrath; very rare. 



1 . Cyrthoceratites lamellosus, nob. Tab. nost., XXVIII. f. 4, 4 a, 4 b. 



Shell conoidal, arched, depressed, covered with raised, lamellar, transverse folds, at equal distances, 

 a little undulated and between which may be observed finer striae, variable in number and also 

 somewhat lamellar. These folds and striae, passing over the dorsal region, turn back to form a 

 scarcely evident groove above the siphon. Longitudinal, rounded, often obsolete folds are also 

 observable toward the middle and upper part of the cone. Septa very slightly concave, elliptical. 

 Siphon small, round, dorso- marginal. The last chamber appears to occupy one-fourth of the 

 shell. 

 When the shell has been somewhat worn by friction the lamellae disappear, and then this Cyrthocera- 

 tite has a very different aspect, only showing fine, very close-set, undulated, transverse striae, which cross 

 the longitudinal grooves. The disposition of the lamellar folds in this species brings to mind the 0. 

 fimbriatus (Sow. Sil. Syst., PI. XIII. f. 20), a straight shell, whose siphon is central. In its form it ap- 

 proaches O. Gesneri, figured by Phillips (Geol. Yorks., Part 2, PI. XXI. f. 6), of which the siphon is also 

 submarginal, but which has no lamellar, transverse striae. But, with regard to the O. Gesneri of Martin, 

 it is a straight shell, and not a Cyrilioceralite. Our species differs from C.Jimbriatus (Phil. Palaeoz. 

 Foss., PI. XLIV. f. 214.) in the greater number and less depth of its longitudinal furrows, by its transverse 

 lamellae being much more serrated, and by its general form being less bent. It differs equally from the 

 C quindecimale o{ the same author (lb., PI. XLIV. f. 216.) by its less serrated lamellae and its less 

 marked longitudinal furrows. 



As the Orthoceratites subpyriformis or Gomvhoceratites approaches the Phragmoceratites, so does the 



