MAMMALS. 215 



The prse-sternum is trilobate in front (figs, 9, 11, 14, 15, 17, p. st.), and is strongly keeled (k.) ; 

 the carination is continued to the end of the proximal "metosteon " (fig. 11, x.) in Scotophiltts. 

 In Plecotus auritus (fig. 17, p. st., f.), the prae-sternum is differentiated into an "ento-," and two 

 " pleuro-sternal " regions by a pair of small " fenestrse." This is exactly like what we see in 

 StcHio (Plate 11, fig. 2, st. f.). 1 The xiphoid segment has an ectosteal " metosteon " in its handle j 

 the broad blade (fig. 11, x.) is ossified by endostosis in old age. The sternal ribs are not 

 segmented from"_the vertebral (s. r., v. r.), and they ossify, not densely, by endostosis. It is common, 

 for the first floating rib to be uncleft from the last sternal rib ; this is seen in Scotopkilus (fig. 11) 

 and in Plecotus. In Molossus this condition exists, but in that type the second floating rib is 

 also continuous with the first. The arrested morphological cleavage of the lower part of the thorax 

 in the Bats is one of the most marked deviations these creatures make from the Insectivorous 

 types. 



Ordo " CARNIVORA." 



Examples. Felis, Thalassarctos, Otaria, Phoca. 



The rest of the Mammalia are possessed of a much more highly developed brain than those 

 which have been spoken of; and are thus the noblest of the Class. Working in a line, I ought to 

 pass at once to the smooth-brained Lemurs, the lowest of the Primates ; but in that way I should 

 reach Man, without coming across the Carnivora, the Cetacea, and the Herbivora (Pachyderms 

 and E,uminants). 



In many respects the Carnivora may be said to form a culminating Order, of this the highest 

 Class ; and yet, for the first time, we find in them the perfect segmentation of a morphological 

 element, which is half cloven from the common mass in my lowest instance (the P^ay). This is the 

 " prse-scapula ;" it forms the foremost of the three scapular bars in the Skate (Plate 1, fig. 2, p. sc.) : 

 in an embryo Kitten (2j inches in length, see Plate XXX, figs. 1 and 2, six and twelve diameters) 

 it is completely severed from the rest of the blade-bone. In the Sloths (Plate XXI, c. s. f.), and 

 in the Ant-bear (Plate XXIII, fig. 21, c. s. f.), the foremost "fenestra" of the Skate (Plate I, 

 fig. 2, c. s. f.), and of the Iguana (Plate IX, figs. 1 and 2, c. s. f.), partly severs both the prse- 

 coracoid and the prse-scapula from the rest of the Shoulder-girdle moiety. In the Pangolins, we have 

 seen the meso-scapula partly separated from the post-scapula by a fenestra, re-adopted, as it were, 

 from the Iguana (Plate IX, figs. 1 and 2, sc. f.), and from the Skate (Plate I, fig. 2, sc. f.) ; but the 

 " meso-" is never separated entirely from the " post-scapula." Hence we see that this complete 

 segmentation of the pra-scapula in the Cat is as little to be accounted for, morphologically, as 

 the perfect cleaving of the " supra-scapula" from the rest of the scapula in the Skate and the 

 Sturgeon a state of things not seen elsewhere. The prse-scapular region of the Cat is seen to 

 be largely produced forwards in the adult ; in the embryo a sinuous tract of connective fibres 

 completely insulates the projecting portion from the root of the meso-scapular spine, which is here 

 very broad (Plate XXX, figs. 1 and 2, p. sc., m. sc.). An ectosteal layer of bone ossifies both the 

 meso- and post-scapular region ; but the pra3-scapula has its own osseous centre. The meso- 



1 M. Blanchard (' L'Organisation du Kegne Animal, Mammif. Cheiropt.,' Livr. ii, PI. 1) has 

 figured these in Vespertilio murinus. 



