MUSCLES OF HEAD AND NECK. 15 



A flat strand of muscle from 2 to 5 mm. wide (Plate 4, fig. 1, e) arises from 

 above the articulation of the 14th rib on each side and passes forward for about 

 60 mm. to become inserted into this great tendinous sheet some 30 mm. posterior 

 to the axilla. This appears to be the dorso-cuticulnris, and is apparently nar- 

 rower than in Gymnura or Potamogale. 



MUSCLES OF HEAD AND NECK. 



Compared with Centetes, Gymnura, or Potamogale, the anterior muscles 

 of the snout seem to show less complexity in Solenodon, but resemble more 

 nearly those of Myogale as figured by Dobson, whose specimen of Solenodon 

 cubanus was in too poor a state of preservation to permit of exact determination 

 of these muscles. 



The platysnia myoides is a flat superficial muscle, well developed and firmly 

 attached to the skin from the lambdoid crest forward along the sides of the face 

 and lower jaw. 



The zygomaticus major (Plate 5, fig. 1, 6) is a relatively small muscle arising 

 from the bony ledge of the antorbital pit just above the last premolar. It 

 passes into a small round tendon at about the level of the anterior incisors, and 

 running just to one sitle of the midventral line, inserts on the ventral portion of 

 the tip of the cartilaginous proboscis. Its action is to depress the snout, but it 

 evidently is of limited use, as the vertical play of the proboscis is not very great. 



The levator labii superioris proprius (Plate 5, fig. 1, c) is a large muscle 

 attached along the entire anterior edge of the orbit from the ventral border of 

 the eye nearly to the dorsal line. It passes forward as muscle to the tips of the 

 nasals where it becomes a flat tendon and runs to the tip of the proboscis below 

 the median line. 



The levator labii s7ipcrioris el erector vibrissarum (Plate 6, fig. 1, a) originates 

 anteriorly to the orbit, between the two nmscles just described and ectal to the 

 opening for the facial nerve. It is likewise more or less firmly attached to the 

 antero-lateral face of the maxillary where it breaks into numerous small thread- 

 like tendons that pass to the bases of the vibrissae with which the snout is 

 well supi)lied. These fibers are firmly united by investing tissue and muscular 

 strands to the side of the cartilaginous proboscis, to which they are undoubtedly 

 able to impart a slight lateral motion. Ventrally this muscle is closely con- 

 nected by tendinous tissue to the orbicularis oris. It is richly supplied with 

 nerves. 



