On the Muscular Anatomy of the Marsupials. 127 



H. Merope, has a very distinct structure, and, I think, may be 

 more nearly allied to the genus Melanagria (Arge). 



4. Hipparchioides mirifica. PI. III. fig. 1. 



? , Lasiommata mirifica, Butler, Ann. & Mag. Nat. Hist. vol. xvii. p. 286 



(1866). 



Hab. ? B.M. 



Two wings and part of the body of this insect are in the 

 National Collection. It is evidently a beautiful insect when 

 perfect. 



XXIII. — On some points in the Muscular Anatomy of the Marsu- 

 pials. By the Rev. Samuel Haughton, M.D., F.R.S., Fellow 

 of Trinity College, Dublin. 

 The following observations were suggested to me by the dissec- 

 tion of several Kangaroos, Phalangers, and Opossums, which 

 were placed at my disposal by the Council of the Royal Zoological 

 Society of Ireland. Several points of much interest turned up 

 in the course of my dissections ; but I shall confine myself at 

 present to a few observations on the cremaster and quadratus 

 femoris muscles, which seem to have escaped the notice of other 

 observers : — 



I. The Cremaster Muscle in the Marsupials, 



Professor Owen thus describes the cremaster muscle : — 

 "The cremaster in the Phalanger and Opossum is not a 

 fasciculus of fibres simply detached from the lower margin of 

 the internal oblique or transversalis, but arises by a narrow 

 though strong aponeurosis from the ilium, within and a little 

 above the lower boundary of the internal oblique, with the fibres 

 of which the course of the cremaster is not parallel j it might be 

 considered as a part of the transversalis, but is separated by the 

 fascia above mentioned from the carneous part of that muscle. 

 Having emerged from beneath the margin of the internal oblique, 

 the cremaster escapes by the large elliptic abdominal ring, bends 

 round the marsupial bone near its free extremity, and expands 

 upon the tunica vaginalis testis. In the female it has the same 

 origin, course, and size, but spreads over the mammary glands 

 at the back of the pouch. If the anterior fascicles of the 

 diverging and embracing fibres be dissected from the posterior 

 ones, the appearance of the cremaster dividing into two layers is 

 produced"*. 



♦ Cyclopaedia of Anatomy and Physiology, vol. iii. p. 288. 



