SCIUEOMOEPHA. 821 



femur, and tibia. Most of these are approj^riate in size to the G. minutus, 

 -which is also the most abundant species. A fragment of a larger femur 

 belongs perhaps to the G. trUophus. 



The humerus is rather slender, and the deltoid crest does not exhibit 

 the prominence so usual in the 3furidce. It is most prominent on the antero- 

 external aspect of the shaft near its middle ; an external as well as an ante- 

 rior ridge diverges from it upwards. The condyles have no intertrochlear 

 ridge, and the external trochlea is not more extended transversely than the 

 internal, measuring from the fundus of the groove. There is a moderate 

 internal epicondyle, and the arterial foramen is distal, and opens anteriorly 

 below and on the external face above. The bridge is slend-er and moder- 

 ately oblique. The external border is acute and twisted. 



The ischium is characterized, like that of other Sciuridce, by the pres- 

 ence of a spine or process which is wanting in North American Muridoe, 

 but is present in Perognathus. The bone is rather short, the tuberosity is 

 "but little enlarged, and the pubic process not very wide. The proximal 

 end of a femur may belong to Eumys elegans, but is too small according to 

 usual data. The great trochanter is elevated as high as the head, from 

 which a deep notch separates it; its posterior fossa is pronounced. The 

 little trochanter is very prominent, projecting at right angles to the shaft. 

 The shaft is broken, so that the presence of a third trochanter cannot be 

 ascertained. The distal end of the femur is characterized by a patellar 

 groove of moderate width, with fairly elevated ridges which are continued 

 Tvell posteriorly on the shaft, but not further than in existing Sciuridce, and 

 not so far as in PaJceolagus. The distal extremity of the tibia displays char- 

 acters of the Sciuridce as distinguished from those of Muridce and Leporidce. 

 'The fibula is of course distinct, and the external trochlear groove opens 

 from its fundus outwards. The internal groove is narrower, and is bounded 

 internally by a vertical malleolus, which has no distal articular facets, and 

 which does not project, but is flat on the inner side. The greater part of 

 the posterior face is occupied by the bones of the Avide groove for the 

 tendon of the flexor longus j^olUcis muscle. Its inferior edge is produced 

 downwards as far as the malleolus, from which it is separated by the deep 

 groove for the tibialis posticus and flexor hngus digitorum muscles. This 



