722 MR FRANK J. COLE 



the anterior surface of the expanded head of the external lateral velar bar. This is 

 the division of the velo-quadratus one sees in a lateral external view in the anterior 

 half of the third fenestra of the skull (figs. 3, 11, v. q'.). 



Dorsal Division (v. </".). — The most dorsal and the largest division of the three. 

 Partly covered ventrally by the middle division. It arose in the same dissection : — 

 (a) a few fibres from the lateral margin of the central expanded portion of the hypo- 

 physial plate ; (b) the greater part apparently from the cranium at a level slightly 

 posterior to the origin of the middle division ; (c) some fibres from the ventro-internal 

 surface of the anterior half of the trabecula behind the origin of the middle division. 

 In the sections the origin was somewhat different. No fibres arose from the cranium, 

 but they all arose from the ventral surface and internal margin of the trabecula 

 opposite the posterior half of the first fenestra of the skull, and also from the lateral 

 margin and dorso-internal surface of the hypophysial plate. 



The fibres of the dorsal division pass backwards and outwards almost parallel, and 

 finally have an oblique insertion into the internal surface of the external lateral velar 

 bar from a short distance behind the free extremity up to and slightly beyond the 

 origin of the internal lateral velar bar. In fact, some of the fibres were inserted into 

 the base of the latter also, although in the sections the insertion terminated immediately 

 in front of the origin of the internal bar. 



The above account differs from P. Furbringer's in several respects, but more 

 particularly in that this author did not find the division of the muscle into three parts. 

 J. Muller mentions two parts in Bdellostoma, which are stated to be antagonistic in 

 action (anatomically quite possible in Myxine) ; but Furbringer disputes the accuracy 

 of this statement, and insists that in Myxine the insertion is quite continuous. 



The velo-quadratus is stated to act as the occlusor of the naso-pharyngeal opening, 

 but the fact that it consists of small plasmic vascular fibres, similar to those of the 

 cordis caudalis, would indicate that it is either a rapid or a rhythmic muscle. Thus the 

 velum may well act as an apparatus which, by a pulsating motion, draws the 

 respiratory water into the pharynx. If this is not so, it is difficult to understand how 

 the water reaches the gills, since the intrinsic and extrinsic musculature of the gills 

 would only expel water from the respiratory apparatus already there. On this view 

 the velo-spinalis is, of course, also a rapid muscle. 



26. M. velo-spinalis. (Figs. 7e, 12, v. s.) 



J. MCller, Anspanner des Schlundsegels (p. 261 and p. 317, A). 



Before describing this muscle, I may mention here a ligament found in its neigh- 

 bourhood. It is of course a part of the general and diffuse ligamentous system found 

 in Myxine, and has a somewhat indefinite origin from the region of the dorso-internal 

 surface of the hyoid arch. It then passes forwards, upwards, and inwards, and is 



