204 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



scapula (cp. fig.). It is these pads that really give articu- 

 lation to the fin rays, and are in fact interposed between 

 the extremities of the fin rays and the scapulo-coracoid. 

 Judging from the analogy of the other fins there may only 

 be one pad normally present in the pectoral fin (cp. pelvic 

 and caudal fins). 



Fin Rays (F.R.). — There were eleven fin rays in the 

 pectoral fin of the specimen now described. Each ray 

 consists of two pieces enclosing a central core of soft 

 tissue, as commonly occurs among Teleosts. Each ray is 

 completely segmented for the greater part of its length, so 

 that on maceration it falls into a number of very small 

 pieces. The two portions of the ray diverge at the 

 scapulo-coracoid articulation and embrace its sub- 

 cartilaginous pad as already described. Each portion also 

 sends down an articular process, and the two of each fin 

 ray clasp the ray immediately below it (cp. fig.), thus 

 giving a rigidity to the fin it would not have were the fin 

 rays independent of each other. Three of the rays were 

 bifurcated at their free extremity in this specimen, and 

 where this obtains both halves of the ray split, the bifur- 

 cation not being due to the two halves diverging. 



"Inter clavicle" (I. CI.). — This bone, of questionable 

 homolog} T . is described last, as it is doubtful what claim 

 it has to the name now given it. It is a median Y-shaped 

 bone — one limb of the Y being horizontal and the other 

 projecting forwards and downwards. It is situated in the 

 muscular cone of tissue passing forwards to the hyoid 

 arch from the clavicle in the middle line between the 

 basal portions of the branchial arches. The horizontal 

 limb is connected anteriorly by four long stout ligaments 

 with the inner face of the lower hypo-hyal of each side — 

 two ligaments passing to each hypo-hyal. Behind it is 

 connected with the clavicle. The arms of the Y are 



