4] 
In Chlamydophorus Macalister* notes this muscle as “very large, 
and related as usual.”’ The muscle is stated by Galton} to be well 
developed throughout the whole of the Edentata, and his paper, as well 
as Gruber’s,t may be consulted for further information. 
Dobson (quoted by Leche)§ notes the presence of the muscle in the 
Talpide. only amongst Insectivora. Gruber, however,|| describes it in 
several others, including Hrinaceus and Sorex. 
It is very largely developed in Talpa.{ 
In Rodents it is almost invariably present as an independent muscle, 
and in the Carivivora also it is usually to be recognised as such. 
The morphology of this muscle is treated of at length in Gruber’s 
and Galton’s papers already referred to.** 
MUSCLES OF THE FOREARM. 
In describing the muscles upon the extensor aspect of the fore- 
arm and hand we may conveniently adopt the schematic classi- 
fication suggested by Dr. Brooksty on the lines laid down by 
_Humphry.tt 
According to this scheme we have to recognise three longi- 
tudinal sectors of the extensor mass in the forearm, each being 
further subdivisible into a superficial and a deep stratum. The 
three sectors are distinguished as radial, ulnar and intermediate, 
and the superficial elements of these may first be described. 
Ordinarily among mammals the superficial radial sector consists 
of Mm. supinator longus and brevis and extensor carpi radialis, 
which may be segmented into “longior” and ‘“ brevior” portions. 
(The supinator brevis is regarded by Brooks as delaminated from 
the more superficial supinator longus. Its description will, how- 
ever, be deferred until the more superficial muscles are noticed.) 
M. supinator longus is unrepresented in Notoryctes. 
This muscle is generally present in Marsupials, but it is lacking in 
Sarcophilus, according to Macalister.$$ Cunningham found it in 
Thylacinus|||| “very feebly developed,” consisting only of a narrow 
fleshy band arising from the upper part of the ectocondylar ridge. In 
Cuscus and Phascogale it was relatively a very large muscle.11 In 
Dasywrus*** it is small and narrow, while in Koalat++ it is enormous. 
In Petawrista taguanoidisttt Haswell found it inserted into the 
scaphoid. Leche$$§ found it united with the extensor carpi radialis in 
Myrmecobius. Macalister||||!} suspects that the muscle described by 
Owen 919 in Perameles as supinator longus is really an extensor carpi 
radialis. St. John Brooks**** holds that the muscle is absent in Orinitho- 
rhynchus, and Meckel++7+ also omitsall mention of it. Neither do Cuvier 
*xxvii., page 248. +txvil., page 171. tlix., loc. cit. §xxvi., page 808 
ix, page 13. Vlix., page 14.. .** lix. and’ xvii. . Tfii., p. xv., and i.. 
pp. 1, e¢ seg. tt xxil., page 46. §§ xxx., page 19. ||lliv., page 13. WIT iv., 
page 14. *** xxxvi., page 123. {tt xxviii., page 130, and Ixxii., page 228. 
ttt xix., page 176. §§§xxvi., page 810. ||||l| xxix., page 164. ‘UIT xlv., 
page 13. ****1., page 9. thf xxxvii, 
