THE SKATE. 39 



postero-inferior one, separated from the preceding by a bar 

 of cartilage, the coracoid fontanelle (c.f). 



45. The separation from the remainder of the girdle of 

 that part which is immediately attached to the vertebral 

 column : this is the supra-scapula (Fig. 10, s.sc], a flat 

 quadrate plate, attached by fibrous tissue to the scapula 

 proper. 



IX. In the pectoral fin, make out 



46. The pro-pterygium (Fig. 10, p.pt), along stout car- 

 tilage, articulated proximally to the anterior glenoid facet, 

 and passing forwards and slightly outwards : it is continued 

 forwards by a series of similar cartilages, of progressively 

 diminishing size, which extend in front of the olfactory 

 capsule, and one of which becomes connected with the 

 antorbital cartilage. 



47. The meso-pterygium (Fig. 10, ms.pi), a flat, com- 

 paratively small cartilage forming the central portion of the 

 attached part of the fin : it articulates with the middle 

 glenoid facet. 



48. The meta-pterygium (Fig. 10, mt.pt), a similar 

 cartilage to the pro-pterygium, which articulates with the 

 posterior glenoid facet, and passes backwards and outwards : 

 it is continued backwards by a series of smaller cartilages, 

 which extend a little posterior to the pelvic girdle. 



49. The fin rays, long jointed rods of cartilage, attached 

 at their proximal ends to the three chief divisions of the 

 fore-limb, and becoming very slender at their distal extremi- 

 ties : a few enter into direct connection with the shoulder 

 girdle, between the meso- and meta- pterygium. 



X. In the pelvic girdle and fins, observe 



50. The hip girdle, 'consisting of a stout ventral bar 

 (Fig. 10, pu) which sends off on each side a forwardly 

 directed pre-pubic process (p-pu) from the external 



