FOSSIL AND EECENT LAGOMOEPHA. 451 



Myolayus Meyeri, Hensel, Zeitschr. deutsch. geol. Ges. viii. p. 699 (185G) : Fraas, Wiirtt. naturw. Jalircsh. 



xxvi. p. 171, pi. V. figs. 2-16 (1870) ; Schlosser, Palseontogr. xxxi. p. 28, pi. xii. fig. 44 {1884). 

 Archceomys steinheimensis , Fraas, Wiirtt. Naturw. Jahresh. xviii. p. 130, pi. ii. fig. 19 (1862). 

 Lagowys ( Miiiilnf/ns) Meyeri, H. v. Meyer, Neu. Jalirb. p. 197 (1804), p. 843 (1865). 

 Layomys rerun, p. p. Fraas, Wiirtt. Naturw. .Taliresh. xxvi. p. 171 (1870). 

 Prolaffus Meyeri, Deperet, Arch. Mus. Lyon, iv. p. 12.3, pi. siii. figs. 18-18 f (1887). 

 Myoluyus sansaidensis, Filhol, Ann. Scienc. geol. xxi. p. 46, pi. i. fig. 8 (1891). 

 Lnyuniys [Prolagus) Meyeri, Deperet, Arch. Mus. Lyon, v. p. .t,j, pi. i. figs. 30, 31 (1892). 



A^'hen publishing liis first note on Lac/oiiii/s-hke E,odents from ffiniagen (1S3G), H. v. 

 Meyer was not aware that two rather diffei-ent forms occur there ; he comprises them 

 both under the name of Lagomys ceningensis. Later on, in his Monograph of tbe fossil 

 Vertebrata from CEningen, he arbitrarily sets aside Konig's specific name for the smaller 

 form, for which he adopts a manuscript name by v. Tschudi, Lagomys Meyeri, found on 

 one of the labels, while he reserves the name Lagomys wnhigensis for the larger 

 form. As stated before, the same author identified the lagomorphine Ptodent from 

 Steinheim with the smaller form from ffiningen ; and in the sequel equally those from 

 several otlier Miocene deposits in Germany. 



On the ground of Pomel's description of the Sansan species, Schlosser adds Lagomys 

 {Frolagi(s) sansaniensis, Pomel, to the synonyms of 3Iyolagiis Meyeri; and likewise the 

 Lagomyidte from the Spitzberg in the Ries, near Nordlingen (Bavaria), referred to 

 Ljagomys rents, Hens., by Fraas (1S70). Filhol has figured as Myolayus sansaniensis 

 (E. Lartet) the type-specimen, a mandilutlar ramus, of Lartet's Lagomys sansaniensis, 

 and is satisfied that " cette espece, comme on le verra par I'examen de la figure grosSie 

 que nous en donnons, etait tres differente de toutes celles qui ont ete deerites " *. It is 

 precisely this enlarged figure of the lower cheek-teeth which shows conclusively that the 

 Sansan fossil is one and the same with the Prolagus species from ffiningen and Steinheim, 

 as conjectured by Schlosser and confirmed by Deperet f, who has added La Grive- 

 Saint-Alban (Isere) %, Mont-Ceindre, and Gray § to the localities of this widespread 

 Middle Miocene species. 



The following descriptions are based on specimens collected at La Grive-Saint-Alban 

 by myself. 



In the genus Prolagus the molars are no longer rooted, and, with the exception of the 

 deciduous teeth, all the cheek-teeth grow from persistent pulps. It does not, however, 

 follow that the triturating surface preserves throughout the animal's life the same 

 pattern. This is the usually accepted belief 1| ; l)ut although the proofs to the contrary 



* Ann. Sc. Geol. xxi. p. 47, pi, i. fig. 8 (1891 ). 



t Arch. Mus. Lyon, v. p. 57 (1892). 



+ Op. cit. iv. p. 167 (18fi7), V. p. r,C, ( 1S94). 



§ Op. cit. V. p. 57. 



II See, e. y., Giebel, in Bronu's ' Khn^en iind Onliumgen des Thierreichs,' vt. v. p. 15:.' {Is75), where he treats of 

 the Rodentia with laminated teeth (" Blatterziihiie "), including the Lagomorpha. He says of them: "Die 

 Kaufliichen dieser Zahne anderu ihre Zeichnung durch Abnutzung nicht."' He might have known better, at least 

 as regards the Hares, from what Hilgendorf had said ten years before (Monatsber. K. Prenss. Akad. d. Wissensch. 

 Berlin, 14 De/.. 1SC5, p. 673) respecting the upper grinding-teeth of young Hares. 



63* 



