451 



occurred was peculiar, as in it the thyroid cartilage had no superior 

 cornua. 



22. A small muscular mento-lryoidean band (Plate V., fig. 2, a), 

 existed single in one subject, but double in another, arising from the 

 inferior surface of the mental ridge on the lower jaw, and running 

 backwards to be inserted into the middle of the body of the os hyoides. 

 Eor the sketch of this muscle I am indebted to Mr. Macmullen. In all 

 instances it was perfectly separate from the digastric. 



23. I have several times found present on the side of the thorax a 

 small or well-developed supra- costalis muscle. Once this occurred in 

 an old though tolerably muscular female. Another instance was in a 

 male subject of enormous proportions; it arose from the lower border 

 of the third or fourth rib, about six inches and a-half from the outer 

 edge of the sternum. On the right side I have generally found it nar- 

 rower and thicker than on the left; it measuredin one instance three inches 

 and three-fourths long, three-quarters of an inch in breadth, and one- 

 eighth of an inch in thickness; but I have seen it much larger. From its 

 place of origin it extended vertically upwards, lying on the upper digita- 

 tions of the serratus magnus, and shortly in front of the respiratory nerve 

 of Bell; then, ascending behind the axillary vein and subclavius muscle, 

 it was inserted into the first rib on the right side, in one instance over 

 the origin of the first slip of the serratus magnus. On the left side in this 

 subject, however, and in several cases on the right, it cleared the bone, 

 and, expanding, was inserted into the deep cervical fascia in the poste- 

 rior inferior triangle of the neck. It lay considerably external to the 

 origin of the lesser pectoral, which covered it, with the intervention of 

 a strong aponeurotic expansion, derived from the deep axillary fascia, 

 and its insertion was placed internal to the scalenus anticus. Mr. 

 Wood has described a somewhat corresponding muscle, which, however, 

 differs from the foregoing in being placed anterior and internal to the 

 serratus magnus ; and, secondly, in having no upper fascial connexion, 

 but being purely costal in its attachments. His slip extended to the 

 fourth rib, and he has described its course as from above downwards ; 

 but as in the most of the instances which I have seen, it evidently acted 

 on the cervical fascia, I have taken the liberty of inverting the order 

 of description. The muscle occurs in several monkeys, in the seal, and 

 in Balcenoptera rostrata. It seems to have no connexion with or rela- 

 tional analogy to the rectus sternalis. 



24. I have met with a distinct extensor ossis metatarsi hallucis, and 

 have also seen this muscle existing as an offshoot from the anterior edge 

 of the tibialis anticus; in the latter subject there existed (25) an ex- 

 tensor primi internodii hallucis, which lay between the former muscle 

 and the extensor hallucis proprius; this latter slip was perfectly uncon- 

 nected with all the surrounding muscles. In an egret monkey I have 

 seen the extensor ossis metatarsi hallucis without any trace of another 

 extensor for the hallux, while in others of the Quadrumana both the 

 extensor ossis metatarsi and the extensor secnndi internodii exist. 



