Brooks — The Osteology and Arthrology of the Haddock. 191 



The post-claviole is a rod-like bone, pointed below, but ex- 

 panded and flattened from side to side above. It is connected to 

 the clavicle chiefly by muscle, the anterior superior angle, which is 

 slightly overlapped by the posterior superior angle of the clavicle, 

 being connected to the latter by a few ligamentous fibres. Its 

 long axis is downwards and slightly backwards, forming an angle 

 of about 45° witli that of the clavicle. 



The supra-claviole (PI. IX., fig. 25, a) is a thick, peg-like piece 

 of bone, sharply pointed below and bevelled internally where it fits 

 into the groove in the clavicle, truncated above and bevelled exter- 

 nally where it is overlapped by the post-temporal, an interosseous 

 ligament binding them together. 



The post-temporal (PI. IX., fig. 25, h) presents a massive, ovate 

 body below, which articulates with the supra-clavicle, and two limbs 

 above — an internal and an external. The internal, which is much 

 the larger, is curved and solid and rounded behind, but thin and 

 excavated on its under surface in front ; it ends in a sharp point, 

 which fits into a groove on the upper surface of the parietal, and 

 just behind this it articulates with the epiotic. The internal limb 

 articulates with the inner surface of the opisthotic. Between the 

 two limbs are four supra-temporals. These are thin, irregular, 

 subcutaneous scales of bone, which are curved so as to form a 

 gutter on their upper surface, which is occupied by raucous glands 

 in the recent state. Three of these are arranged end to end along 

 the inner limb, lying close to the epiotic and parietal. The other 

 lies near the outer limb, and is applied against the pterotic. 

 Behind these four is a much smaller scale, which occupies the 

 posterior part of the notch on the upper surface of the bone, at the 

 junction of the inner, limb and the body. This may be a fifth 

 supra-temporal, or the first "lateral line bone."' 



The mesopterygial basale is represented by the piece of carti- 

 lage which is embraced by the base of the anterior fin-ray. Below 

 and behind this are the three radialia and the metapterygial basale. 

 These are small hour-glass-shaped bones, with the exception of the 

 first, or anterior radiale, which is somewhat semilunar in form. 

 They are connected to a strip of cartilage which occupies the 

 bifurcation of the proximal ends of the fin-rays. 



^ Cf. Parker on Cottus biibalis {op. cit., page 43). 



