348 GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION. 



habits the Atlantic slope from Nova Scotia to South Carolina, and 

 westward to Oregon), Scapanus, and Scalops, the last (Scalops 

 aquaticus) the common American form, whose range covers the 

 greater part of the North American continent east of the Rocky 

 Mountains. A somewhat aberrant form, Neurotrichus Gibbsii, 

 found in the Western United States (Cascade Mountains to Texas), 

 has its analogue in the Urotrichus of Japan, to which genus it has 

 generally been referred, and from which it differs mainly in the 

 dental formula. Fossil remains of Talpidse date back to the Eo- 

 cene period (Prototalpa, Quercy, France ; Talpavus, Wyoming), 

 but the genus Talpa itself is not known prior to the Miocene ; the 

 common European species is found in the Quaternary deposits. 

 Myogale (with Palseospalax and Galeospalax) occurs in the Miocene 

 and Pliocene deposits of France and England respectively. None 

 of the existing American genera have as yet been found in a fossil 

 state. Other insectivorous forms, however, known principally in 

 a fragmentary condition, and not impossibly referable, at least in 

 part, to the type of insectivorous Marsupialia, have been described 

 from the Eocene of Wyoming and New Mexico (Passalacodon, 

 Centetodon, Entomodon, Entomacodon, Triacodon, Esthonyx), and, 

 together with a number of Miocene forms from Dakota and Colo- 

 rado (Leptictis, Isacis, Ictops), constitute a distinct family, Lep- 

 tictidae. 



Insectivorous Forms of Doubtful Position. Numerous insec- 

 tivorous animals, known largely by portions of their dental armature 

 alone, are found in the older (principally Eocene) Tertiary deposits 

 of France and the western territory of the United States (Wyoming, 

 New Mexico). They are not improbably, as Professor Cope sug- 

 gests, referable in part to the lemurs, although from their imperfect 

 state of preservation it is in many or most cases impossible to de- 

 termine their true relationship, whether with the class of animals 

 just mentioned or with the true insectivores. By Trouessart they 

 are all ranged with the Insectivora as the group of the protolemurs. 

 Among the better known of these forms are Microsyops, Pataco- 

 don, Hyopsodus, Sarcolemur, Tomitherium, Notharctus, Necro- 

 lemur (supposed by Filhol to have its nearest ally in the galago of 

 Africa), Adapis (Pala3olemur), and Protoadapis, the last three from 

 the Eocene of France, and representing distinctively lemuroid types. 

 Galerix is from the Miocene deposits of the same country. In the 



