INSECTIVORA OF THE SANTA CRUZ BEDS. 373 



and the bicipital groove is not so deep, while the shaft is more slender ; 

 the crest for the attachment of the pectoralis major muscle is even more 

 prominent and more acutely pointed, and is situated rather more proxi- 

 mally upon the shaft. The supinator ridge is enormously developed in pro- 

 portion to the size of the bone. The internal epicondyle has almost as 

 extreme a development as in Chrysochloris, though the process is some- 

 what shorter and extends rather less internally and more distally; the 

 foramen is very small. The distal trochlea is broad but very low; the 

 facet for the capitellum of the radius is much broader, but less prominent, 

 and less spheroidal in shape than in the African type. The anconeal fossa 

 is a mere transverse, shallow groove. The humerus of Notoryctes closely 

 resembles those of the two insectivorous genera, though differing in some 

 respects from both of them. The deltoid ridge, which is not apparent in 

 the latter, is very prominent and ends in a process for the pectoralis major. 

 The supinator ridge is exceedingly large and the internal epicondyle is 

 very much as in the two Insectivora, but it lacks the foramen, and the 

 shaft is so twisted that the epicondyle has received a more backward direc- 

 tion. The trochlea resembles that of Necrolestes in the shape of the facet 

 for the capitellum of the radius. 



The forearm bones (Plate LXIV, Fig. 5) of Necrolestes are strikingly 

 like those of Chrysochloris with differences of only minor importance. 

 The radius has a less discoidal and more broadly oval head, which has a 

 quite deeply concave facet for the median convexity of the humeral trochlea ; 

 the shaft is stouter than in the African type and has a more distinctly 

 marked lateral curvature ; proximally its position is on the external side 

 of the elbow-joint, but it crosses the ulna, running most of its course in 

 front of the latter, while distally it is internal ; the distal end is relatively 

 broad and its anterior face is grooved by shallow sulci for the extensor 

 tendons. The ulna has a remarkably elongate olecranon, which closely 

 resembles that of Chrysochloris, but is rather shorter and broader ; the 

 process is sickle-shaped and curves toward the internal side of the arm, 

 or mesially, with the external border convex and the inner one concave ; 

 this curvature is more pronounced than in Chrysochloris; the anterior face 

 of the process is almost plane, but the posterior face is made convex by a 

 prominent median ridge. The sigmoid notch is a short, but deep trans- 

 verse - groove and the coronoid process forms a prominent ridge. The 

 shaft of the ulna is stouter than in the golden moles and the distal end is 



