No. 468.] MUSCLES OF ACANTHIAS AND RATA. 9II 
the direction of its fibers somewhat resembles it although it does 
not in all respects fulfill the conditions found in Acanthias. 
There are here three parts to the muscle: a small median por- 
tion and two more lateral in position. 
The median, the smallest, arises from the side of the first 
vertebra and its fibers run obliquely backwards to be inserted on 
the anterior edge and ventral surface of the suprascapula. The 
most lateral portion arises near the first and its fibers run ob- 
liquely backward and outward to the insertion upon the upper 
surface of the last visceral arch and on the anterior edge of the 
girdle far down towards the ventral edge. The remaining por- 
tion arises just ventral to the part just described and its fibers 
are attached to the scapular portion of the pectoral girdle. (In 
Raia radiata the median portion is greatly reduced and its origin 
is from the lateral process of the vertebra, just back of that of 
the next division.) 
The two lateral portions of the muscle in Raia are apparently 
partly antagonistic, that first described elevating, the other de- 
pressing the girdle to a certain extent. 
Levator Labialıs Superioris. 
Acanthias. 
Although Vetter classifies this muscle among the adductors 
he says (74, p. 448): “Er erscheint als seriales Homologon 
des M. levator max. sup. und aller der andern Theile des gros- 
sen Constrictors, welche vom Schadel oder von der epaxionischen 
Muskulatur zu der Visceralbogen gehen, und ist sonach passen- 
den als M. levator labii sup. zu bezeichen." For this reason I 
have included it among the other similar constrictors. This 
muscle (Fig. 1, Z/s) has its origin from the ventral surface of 
the cranium, in front of the basal process and to one side of the 
middle line. The fibers run outwards and backwards, describ- 
ing an arc to the angles of the mouth where they converge to a 
straight fibrous tendon which passes dorsal to the labial carti- 
lages, crosses the angle of the mouth at right angles, and is 
inserted among the fibers of the adductor mandibularis. 
