1865.] ANATOMY OF NYCTICEBUS, 2i1 
published as the result of reiterated observations, and as the final 
settlement of points previously disputed between them, might per- 
haps have been expected to have rendered unnecessary any further 
publication of anatomical facts respecting the genus therein described, 
excepting details of an obscure or recondite character. 
Nevertheless our dissection of a specimen of Nycticebus tardigra- 
dus, recently received from the Society’s Gardens has been the occa- 
sion of observations which we consider are worthy of special men- 
tion. 
The disposition and arrangement of the muscles and tendons so 
differ from the description given by these authors, that we cannot 
consider them as merely the result of individual variation. 
We are, indeed, inclined to think that, in the memoir on the genus 
Stenops, the authors have not sufficiently distinguished, or been 
So precise in noting, the special differences of the three forms in- 
cluded by them in that genus, as is desirable in such interesting 
animals. 
In their memoir seventy muscles in all have been mentioned, but 
of many of these there is no more than a passing notice. We have 
therefore endeavoured to supplement what they have given meagrely, 
adding an account of other muscles not alluded to by them. 
To each of the latter we have appended an asterisk, to distinguish 
them from those already mentioned by the authors. 
Muscles of the Head and Neck.—The digastric we found exceed- 
ingly strong. It arises from the mastoidal region, and is inserted as 
usual. There is a distinct median tendon as in Tarsius! and Chei- 
romys, but without the “two fasciculi of muscular fibres’? to the 
posterior bellies existing in the latter genus. 
The muscles attached to the ventral surface of the neck are re- 
markable. Their great length and thickness have been mentioned 
by Profs. S. Van der Kolk and Vrolik, but they are spoken of only 
as “muscles longs du cou (mm. longi colli).” 
It is not, however, the longus colli which is so very much enlarged, 
but the rectus capitis anticus major ; and it attains a truly prodigious 
size. It arises from the front of the bodies of the vertebrze as low 
down as the sixth dorsal, and is inserted into the basioccipital for 
almost the whole length of that bone, also into the transverse pro- 
cesses of the axis and other cervical vertebree (fig. 1, R. c. a. map.). 
Meckel? is silent as to the conditions of this and the following 
muscles in the Primates ; but he notices a similar excess of this muscle 
over the longus colli in the Beaver. In Tarsius‘ this muscle is large, 
but does not come from the dorsal vertebree ; but in Ateles belze- 
buth, Kuhl° describes it as arising from the side of the third thoracic 
vertebra, 
The rectus capitis anticus minor is pyramidal in shape, and arises 
* Burmeister, ‘ Tarsius,’ p. 34, t. 5. fig. 13, 14, 7. 
* Owen, Trans. Zool. Soc. vol. v. p. 58. 
> Anat. Comp., tiaduit par MM. Riester et Alph. Sanson, 1830, vol. yi. p. 173. 
* Burmeister, op. cif. p. 39, t. 5. fig. 14 n. 
* Beitriige z. Beschreibung meherer Mammalien, p. 9. 
Proc. Zoot. Soc.—1865, No. XVI. 
