10 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 45. 



and second sacrals in Twpaia are practically devoid of dorsal spines, 

 but the thii'd has a conspicuous one. All three have distinct spines 

 in Macroscelididse, and that of the first is very large and conspicuous. 

 The sacrum is attached to the ilia by means of the transverse proc- 

 esses of the first sacral vertebra in Twpaia, by those of the first and 

 second in Macroscelididse. The first five caudal vertebra m Twpaia 

 have a neural canal and well-developed transverse processes; in 

 Macroscelididse it is only the first three. 



Rihs and sternum. — There are 13 pairs of ribs in Tupaia, of which 

 the first 8 are attached along their ventral border directly to the 

 sternum, the seventh and eighth reaching the sternum together, 

 where the xiphoid segment of the sternum is attached to the fifth 

 mesosternal segment. The ventral ends of the last two pairs of ribs 

 are entirely free, while the ventral ends of the ninth, tenth, and 

 eleventh ribs are attached to the costal cartilages of one another and 

 to that of the eighth rib. 



The sternum consists of a large well developed manubrium, the 

 anterior extremity of which is largely expanded, as is usual in mammals 

 with a well developed clavicle, and relatively better developed than 

 it is in Macroscelididse. The manubrium is followed by five narrow 

 mesosternal segments, and these in turn by the narrow xiphisternum 

 ending in a rather distmct fiat rounded piece of cartilage. In Macro- 

 scelididse there are only four distinct and very wide mesosternal seg- 

 ments, and the posterior extremity of the xiphisternum is forked. 



Shoulder girdle. — ^The clavicle is well developed in Tupaia, articu- 

 lating at one extremity with manubrium of the sternum and at the 

 other with the acromion process of the scapula. It appears to be 

 relatively as well developed in Macroscelididse. 



The scapula presents no special peculiarities; its shape may be 

 seen from an examination of plate 2. It possesses a flat wide 

 acromion process and a short blunt metacromion. The coracoid 

 process is well developed. The spine of the scapula is relatively 

 much longer in Tupaiidse than in JMacroscelididse, and conversely the 

 acromial process relatively shorter. 



Pelvis. — ^All three bones of the pelvis are well developed in Tupaiidse, 

 the ilia are large and flaring and relatively wide, the tuberosity of the 

 ischium well developed, and the symphysis pubis very long, and the 

 obturator foramen large and oval. In Macroscelidid^ the ilia are 

 much narrower, the symphysis relatively shorter, and the obturator 

 foramen more oblique and elongated. 



Fore limh. — The humerus is long and weU developed and shows no 

 special peculiarities. The deltoid ridge is prominent and begins 

 slightly above the middle of the shaft. A distinct supracondylar 

 foramen is above the internal condyle relatively smaller in Tupaiidae 



