ANATOMY OF THE LEMUROIDEA. 17 
thoracic portions of this muscle are said to be quite divided and to be so broad at its 
insertion as to meet above its fellow of the opposite side. 
In Loris gracilis both portions of this muscle are largely developed’. 
In Nycticebus tardigradus it is as in Lemur catta. 
Burmeister describes this muscle as divided into two in Tursius*, viz. (a) the cleido- 
mastoideus or larger portion, and (4) the sterno-mastoideus the smaller part. ‘The 
former (a) arises from the upper border of the clavicle and is inserted upon the curved 
line of the occiput. The latter (4), a rounder muscle, springs from the upper end of 
the sternum, and is inserted into the skull behind the ear, but before the first part of 
the muscle. 
Owen says that in Cheiromys* it is as we have above stated it to be in L. catta, except 
that the cleidal portion arises from the middle third of the clavicle. 
SrerNno-Hyo1D.—This muscle arises deeply within the thorax from the upper or inner 
surface of the sternum between the cartilages of the second and third ribs. It is 
inserted into the os hyoides just within the insertion of the omo-hyoid. It is closely 
united with its fellow of the opposite side. 
Cuvier represents in Lemur varius the two sterno-hyoids as fused into one single 
muscle (/.¢. pl. 68. fig. 1,2). In his pl. 69. fig. 1 the same muscle is erroneously 
marked y. 
In Galago crassicaudatus (P1. III. fig. 5, S.hy, S.hy*, and S.hy**) it is much as in 
Lemur, as is also the case in Loris gracilis * and Potto °. 
Each muscle is broad, but presents no difference in its attachment in Tarsius°. 
In Chetromys Owen’ says merely “they gradually contract as they ascend,” and are 
closely connected together in the middle line. 
The STERNO-THYROID also has origin deeply within the thorax and in common with the 
sterno-hyoid. It is inserted into the outer side of the posterior (lower) border of the 
thyroid cartilage, partly figured by Cuvier in his ‘ Myologie,’ pl. 68. fig. 1, x', and also 
in pl. 69. fig. 1, where it is wrongly marked y', which letter in the list of muscles is 
said to designate the thyro-pharyngien ! 
In Galago crassicaudatus (P\. III. fig. 5, 8.th) as in the genus Lemur. 
At the sternum these muscles are hardly resolvable into two bellies in Tarsius*. 
Tuyro-HY01D.—This is as usual a continuation of the last, going from the outer side of 
the thyroid cartilage to the posterior cornua of the os hyoides. It is indicated by 
Cuvier in his ‘ Planches de Myologie,’ pl. 68. fig. 1, y. For this muscle in Galago cras- 
sicaudatus see Pl. III. tig. 5, Th.h. 
The Omo-Hyorp is a very long and slender muscle, broader, however, anteriorly 
(above) than at its scapular end. It arises from the most prominent point of the 
1 Cuvier, 7. c. pls. 6 & 7. figs. 1 & 2, a, b, b’. > Loe. cit. p. 37, tab. 5. fig. 13, a, b. 
3 Loc. cit. p. 58, pl. 22. figs. 1, 9, 9'. * Loe. cit. pls. 6 & 7. fig. 2, x. 5 Loc. cit. p. 25. 
® Loc, cit. p. 34, tab. 5. fig. 13, a. 7 Loe. cit. p. 58. ® Loc. cit. p. 34, pl. 5. fig. 12, ¢. 
VOL. VII.—PART I. D 
