1.54 NATURAL HISTOKY. 



This species occurs abundantly in the Miocene lacustrine limestone near Issoire. A second species 

 (/. minor} has been detected in the Upper Eocene of Lamaiidine-haute. 



Of the OCTODONTID.E. an essentially American family at the present day, nearly all the recorded 

 fossil forms are also American. Species of Echinomys, Loncheres, and Phyllomys were obtained by Dr. 

 Lund from the Brazilian bone-caves, which also furnished him with the remains of a Coypu (Myopotamus 

 antiquus), and of an allied form, Carterodon sulcidens, distinguished by its having broad incisors with 

 longitudinal furrows and raised ridges. The latter has since been found living in South America. 

 Another species, allied to Eckinomys, is named by Lund LoncUopliorus foss'dis. The superficial deposits 

 of South America have yielded the remains of two species of Ctetwmys, one of which is believed to be 

 identical with a recent species. As several species of this family now live in Africa, the occurrence 

 in the eastern hemisphere of fossil forms belonging to it would not be surprising, but the few that have 

 been referred to it are of very doubtful nature. M. Lartet obtained some isolated teeth from the 

 Miocene of Sansan, which he described under the name of Myopotamus sansaniensis ; and one or two 

 other types (Aulacodon, Adelomys), from Upper Eocene and Miocene beds, are of very uncertain position. 



Of the HYSTRICID.E, or Porcupines, remains have been obtained in both hemispheres. In the 

 Old World traces of true Porcupines (Hystrix) are recorded from the Valley of the Arno, from the 

 Sivaliks, the Pliocene deposits of the Auvergne, from Pikermi, and, on very doubtful evidence, from 

 the Upper Eocene of Lamandine-basse ; whilst Dr. Leidy has described two teeth from the Pliocene 

 deposits of Dakota, as belonging to a species (Hystrix venustus) allied to the European Porcupine. 

 This determination, if confirmed, would be of great interest, as no true Porcupine now occurs in 

 America. Of the American type, two species of Sphingurus have been obtained from the Brazilian 

 bone-caves ; and Professor Cope records a species of the North American genus Erythizon from a 

 similar cave in Pennsylvania. 



The CHIXCHILLID.E have left but scanty traces of their former existence. Lagostomus brasiliensis 

 is from the Brazilian bone-caves ; and Megamys patagoniensis from the Eocene sandstone of Patagonia. 

 The latter species is founded upon a tibia and rotula, which on comparison seemed to approach most 

 nearly to those of the Rodents of this family, and if the determination, be correct it was probably 

 one of the largest species of the order, as the tibia measures about a foot long. AmUyrkiza and 

 Loxomylus, are two genera described by Professor Cope from bone-caves in Anguilla Island, West 

 Indies. 



The DASYPROCTID/E have but few fossil representatives, and the undoubted ones are all from the 

 bone-caves of Brazil, which furnished Dr. Lund with two Agoutis and two Pacas. Of the former, 

 one is described as Dasyprocta capreolus ; the second is allied to the living D. caudata. The two 

 species of Ccelogenys are extinct. Some teeth, found in Tertiary deposits of the Puy-de-D6me, have 

 been referred to Dasyprocta, but this determination is excessively doubtful. Diobroticus schmerlingi 

 from Belgian caves has been placed with the Castoridse. 



Of the CAVIID.E, Dr. Lund obtained three species of the genus Cavia, and two of Hydrockcerus, 

 from Brazilian bone-caves. Of the latter, one was allied to the existing Capybara ; the other was a 

 gigantic species, measuring about five feet in length. Dr. Leidy has described a species (Hydrochoerus 

 cesopi) from teeth found in Post-Pliocene deposits in South Carolina ; and the Pampean deposits of the 

 same age furnished M. D'Orbigny with the remains of a Cavy (Cavia antiqua) which, however, is 

 doubtfully distinct from the Patagonian species. 



The remains of species of the family LEPORINE are very abundant in some Post-Pliocene cave 

 deposits on both sides of the Atlantic, and in several cases the species are evidently identical with 

 those now living. Besides these, species of the genus Leims have been found in Pliocene and Miocene 

 beds in France. In North America three extinct Leporine genera have been recognised, differing from 

 Lepus in certain peculiarities of the molar teeth : PalcKolagus, with three species, from the Miocene of 

 Dakota and Colorado ; Panolax, from the Pliocene marls of Santa Fe ; and Praot/terium, from a bone- 

 cave in Pennsylvania. The last-named genus has the crowns of the molars transversely oval, and 

 without the enamel-band or crest which is seen on the surface of the teeth of other Hares. 



The LAGOMYID.E are known in a fossil state chiefly from Post-Pliocene deposits, and the bone 

 breccias of caves in various parts of Europe. In Post- Pliocene times the genus Lagomys seems to have 

 been very generally distributed over the South of Europe ; and the earliest appearance of the genus 



