1897.] NEW YORK ACADEMY OF SCIENCES. 343' 



whole, with the exception of the abdominal portion, is best illus- 

 trated by Man himself. The extensive clavicular and sterno- 

 costal origin necessitates, however, the crowding together and 

 folding of the resulting muscular sheet, which finds expression, 

 at the comparatively short line of the humeral insertion, in the 

 reduplications and layers of the terminal tendon. 



4. The fusion of the tendon of the clavicular portion with the 

 superficial surface of the tendon of the sternal division also cor- 

 responds exactly to the arrangement of the muscle in Man, and 

 the union of the clavicular Pectoral and Deltoid repeats the con- 

 dition presented by most monkeys and by man as a variation. 



The entire Pectoral group expresses the intermediate position 

 of the Lemuroidea, as standing between the higher Primates 

 and lower mammalia. In Lemur hruneus the development of 

 Primate characters appears to have proceeded further than in 

 the other forms examined. This is especially so in regard to 

 the insertion of the Pectoral grouj); but even at the origin, 

 while the Ectopectoral is in its central portion still confined en- 

 tirely to the Sternum, the deeper p]ntopectoral has already as- 

 sumed in part the costal origin characteristic of the higher 

 forms. The lateral deviation of the abdominal origin of the 

 Ectopectoral has a similar significance. 



2, SUBCLAVIUS. 



(PI. XXVIII.) 



This is a fairly well developed muscle, arising from the ven- 

 tral surface of the first costal cartilage, just lateral to the sterno- 

 clavicular articulation, between it and the attachments to the 

 first rib of the Rectus, Supracostalis and Scalenus (PL XXVII J). 



The muscle is inserted into the dorsal grooved surface of the 

 middle third of the clavicle. 



The Subclavius appears to be constant throughout the sub- 

 order, and only differs in the various genera in reference to the 

 extent of the attachment to the clavicle. 



Murie and Mivart CI, p. 27) describe it in Lemu?' catta as 

 inserted into the outer two-thirds of the clavicle, and especially 

 into the " concavity in the hinder (under) surface of the bone 

 toward its distal or outer end." 



Cuvier (H, PI. LXVIII, fig. 1, h) represents the insertion in 

 L. varius as extending outward but little beyond the middle of 

 the clavicle. 



Murie and Mivart (1. p. 27, PI. III., fig. 5, Sb.) describe and 

 figure the muscle as relatively stronger in Galago crassicauda- 

 tua and in G. allenii, and as inserted only into the middle third 

 of the clavicle. 



