THE SHOULDER-GIRDLE IN FISHES. 43 



Fam. COTTID.E. 



v 



Example 1. Coitus bubalis, Euphrasen. 



My first instance is the best connecting link between the Ganoid and Sub-ganoid 

 types already described and the true typical Teleostei, the Percoids and their allies ; 

 moreover, another Cottoid the Pogge (Agonus cataphractus] reassumes the ganoid covering. 

 In the Fatherlasher (Coitus bubalis), I first saw that the so-called supra-scapula was nothing 

 more nor less than the first " lateral-line " bone, connecting that series Avith the " supra- 

 temporals." Plate II, fig. 12, s. t., is the last of that series; and p. t. is the "post-temporal," a 

 scabrous scale, which is two-legged, and is attached in the usual manner to the occipito-otic 

 region. There is a much larger bone below this, the " supra-clavicle " (s. cl.) ; it is rough at 

 the top, and sends downwards and backwards a large flat blade ; this blade is tied obliquely 

 across the scooped upper part of the huge clavicle. This latter bone (cl.) reaches nearly as 

 high as the vertebral spines, whilst below it meets its fellow of the opposite side at the 

 abdominal line. Below the obliquely scooped upper part of the clavicle the bone looks forwards 

 and inwards, and for some distance there is very little posterior growth ; below the scapula this 

 posterior plate begins, and is very strong; it increases in breadth very rapidily towards the lower 

 part. This lower, longitudinally vertical plate of the clavicle answers to a great degree to the 

 inter-clavicular plate of the Ostracion (fig. 4, A and B, i. cl.), and to the two inter-clavicles 

 of the Syngnatlius (fig. 3 A, a. i. cl., p. i. cl.) ; but not altogether, for there are two additional 

 ossicles (Plate II, fig. 12, a. i. cl., p. i. cl.) in Cottus bubalis. The first of this, the "anterior 

 inter-clavicle," is a small oblong bone, occupying the posterior angle of the plate ; the " posterior 

 inter-clavicle," is a much larger plate ; it is oblong, with a produced point below ; these plates 

 are all on the inside the coracoid. Here we see that the Cottus is ascending in the scale 

 towards the typical Fish ; and these feeble inter-clavicles are to a great degree aborted by the 

 main clavicle ; and have no power to arrest the coracoid in the manner shown in Gasterosteus and 

 Ostracion ; yet their presence is to me most unexpected, and very instructive. The post-clavicle 

 (p. cl.) is a rather feeble, gently arcuate, and bluntly styloid bone ; it reaches to the middle of 

 the brachial series below. The scapula of Cottus (sc.) is largely cloven in front by an obliquely 

 oval notch (sc. n.) ; above, it articulates (by harmony) with the posterior edge of the clavicle ; 

 below, it rests its squared base upon the top of the great posterior plate of the clavicle ; behind, it 

 sends a periosteal layer over the two upper brachials. It is wholly separated from the top of the 

 prse-coracoid for the whole space, and more, of the depth of the greatest brachial ; the lowest but 

 one (see Plate II, fig. 12, sc. cr.). The four uppermost (dermal) pectoral rays (p. r.) articulate 

 directly with the scapula, and its posterior or glenoid margin, receives the two upper brachials 

 (b.). Both the scapula and coracoid are converted into dense bone in Cottus bubalis ; the 

 latter bone sends upwards a narrow glenoid band (p. cr.), and this part forms an obtuse angle 

 with the head of the bone ; into this angle the lowest brachial (b. 4) fits. Where the prse-coracoid 

 and coracoid regions unite at an extremely open angle, the coracoid foramen (cr. fo.) is seen ; 

 the main part of the bone is a phalangoid ray ; it is broad at the base, nearly reaches the bottom of 

 the clavicle, and lies in the right-angled space between its front and hinder plates. 



