A. H. Foord — Orthoceras vaginatus. 355 



it is not my purpose here to attempt to determine. That no ordinary 

 floods such as now occasionally occur in the winter months, effected 

 the work of erosion in the Kaura and Dueira districts is a fact that 

 no one would feel inclined to dispute, after seeing the precipitous 

 and rugged sides of the Kaura Gorge, a valley of erosion that lies 

 a few hundred yards to the north of the Dueira valley. The 

 denuded condition of the surface in these localities points to the action 

 of torrential volumes of water ; and it was, probably, to the occasional 

 overflow of these from their ox'dinary channels, combined with the 

 transporting action of the rain on the slopes, that the deposits that 

 form the subject of this article owe their origin. 



III. — On Oethooebatites vaginatus, Schlotheim. 



By Arthur H. Foord, F.G.S. 



Royal Dublin Society. 



I HAVE lately been favoured by Dr. W. Dames with a separat' 

 copy of a communication made by him to the Neues Jahrbuc 

 fiir Mineralogie, etc.,^ dated Berlin, 18th December, 1890, in whic x 

 he points out that in my Catalogue of Fossil Cephalopoda, British 

 Museum (Nat. Hist.) part i. (1888) I have (following Eichwald^) 

 wrongly referred a certain " smooth " species of Endoceras from 

 Reval in Esthonia, to the Orthoceratites vaginatus of v. Schlotheim, 

 — a ribbed species. Dr. Dames states, in the above communication, 

 that he was asked by Dr. Lindstrom of Stockholm (at the time 

 when the latter was occupied with his edition of the " Fragmenta 

 Sihirica ") if he could inform him to what species v. Schlotheim 

 had given the name Orthoceratites vaginatus. Dr. Dames' reply to 

 this question was inserted by Dr. Lindstrom in the midst of a very 

 full table of synonymy of Orthoceras \Eudoceras~\ vaginatum,^ and in 

 that rather obscure situation it escaped my notice. The reply in 

 question was to the effect that the examples of v. Schlotheim's type, 

 sent by Dr. Dames from the Berlin University Museum to Dr. Lind- 

 strom, were without doiibt v. Schlotheim's species.* The latter 

 (widely distributed in Esthonia, Sweden, and Oeland^) has more or 



^ 1891, Band i. Zweites Heft. Breifl. Mittheil. ii. p. 210. 



2 Leth. Eossica, 1860, vol. i. p. 1243. 



^ Fragmenta Silurica, Angelin and Lindstrom. 1880, p. 2. 



* The following is a translation of v. Schlotheim's description of " Orthoceratites 

 vaginatus" (Petrefactenkunde, 1820, p. 63): — "Very beautiful and instructive 

 examples from Reval, in Ueberg. Kalkst., some part still in the matrix, some free, 

 and only about five inches long to a diameter of one inch ; besides separate pieces of 

 its remarkable siphuncle. Cf. Knoir, pt. iii. suppl. t. iv5. and Breynii opuscula, 

 t. V. f. 2b., where this Orthoceratite, together with its elegant, somewhat cylindrical 

 siphuncle is tolerably well portrayed. The length and thickness attained is, it 

 appears, very considerable, whilst the siphuncle belonging to it is found of consider- 

 able stoutness. Its relation to the other part of the Orthoceratite is so important 

 that it almost appears as a part of the shell-wall of the latter. It runs, moreover, 

 close to one side of the shell, which in most of the representations of it is not 

 properly indicated, and its protuberances have somewhat of a screw shape ; very 

 ornamental, as if elaborately designed. The shell itself is very distinctly oblique, 

 with sharp, somewhat forwardly projecting lines, striated in the direction of the 

 chambers, which latter are bent inwards somewhat stronger towards the siphuncle." 



* An island in the Baltic, ofi the east coast of Sweden. 



