98 DESCRIPTIONS OF PREPARATIONS. 



therefore probably in others as well, while the clavicular process (=praecoracoid 

 process of his paper) increases in size, and forms what is generally termed coracoid. 

 The dorsal angle of the scapula of the Pike bends inwards and downwards in 

 development. In Cyprinoids, in the Salmon, &c., a curved bar of bone stretches 

 from the dorsal angle of the scapula to a spot ventral to the scapular foramen. 

 This bar in the Cyprinoid is derived, according to 'Swirski, from two processes of 

 the scapula, a dorsal and a ventral, which meet and fuse. They appear in a late 

 stage of development. 



In the bony Ganoidei the proximal end of the metapterygium of the ventral fin 

 bears a cartilaginous process. Davidoff regards this as pelvic, but Wiedersheim 

 considers it to be part of the metapterygium. The two metapterygia are always in 

 contact at their proximal extremities, but often widely separate distally, e.g. bony 

 Ganoidei, the Pike, &c. ; or a bar of bone may develop at the distal end of each 

 metapterygium, and meet its fellow in the middle line, while a space separates the 

 middle portion of the two bones, e. g. Salmon ; or the two may be in contact through- 

 out the whole extent of their median edges, e. g. in the Perch ; or finally, complete 

 fusion may take place. 



The basal cartilages or bones which articulate with the coraco-scapular are five 

 in number. The first is included in the first fin-ray, and represents a propterygium; 

 the fifth is long and is a metapterygium. In some Teleostei the number is reduced, 

 or the bones may be entirely lost. A row of small radial cartilages is to be found 

 in some instances inclosed in the bases of the fin-rays. They do not seem to be 

 present in the Perch, at least not in the adult. The fin-rays of the pelvic fins 

 articulate directly with the metapterygium. A row of excessively small bony or 

 cartilaginous particles representing radials is sometimes inclosed in their bases. 

 They do not exist however in the full-grown Perch. 



For the caudal canal and interspinous bones, see next Preparation, pp. 100, 101. 



Skull of Salmon. W. K. Parker, Ph. Tr. 163, 1873; cf. Id. and Bettany, Morpho- 

 logy of the Skull, London, 1877. Cod. T. J. Parker, Zootomy, London, 1884. Pike 

 (and other fisJi). Huxley, Lectures on Elements of Comparative Anatomy, 1864. 

 Investing bones of Pike's head. Walther, J. Z. xvi. 1882. Loricaria, &c. Goldi, ibid, 

 xvii. 1883. Characinidae (and auditory bones). Sagemehl, M. J. x. 1885. 



Azygos fins. Kolliker, Uber das Ende der Wirbelsaule der Ganoiden, &c., 

 Leipzig, 1860. Caudal. Lotz, Z. W. Z. xiv. 1864 (Perch, p. 89); Development of', 

 Agassiz, Proceedings Amer. Acad. (new series) v. 1878; vi. 1879: ix. 1882; cf. 

 Balfour and W. N. Parker on Lepidosteus, Ph. Tr. 173, 1882, and Grassi, M. J. viii. 

 1882. 



Fatty fin of Salmonidae. De la Valette St. George, A. M. A. xvii. 1880. 



Ichthyopterygium and Cheiropterygium. Baur. Z. A. viii. 1885; cf. Balfour in 

 Comparative Embryology, ii. pp. 500-511 with references. 



Shoulder-girdle. 'Swirski, Schultergiirtel des Hechtes (Inaug. diss.), Dorpat, 

 1880; W. K. Parker, Ray Society, 1868; Gegenbaur, Untersuchungen zur Ver- 

 gleich. Anat. der Wirbelthiere, ii., Leipzig, 1865. 



Pelvis, Wiedersheim, M. J. vii. 1881 ; von Davidoff, M. J. v. 1879 ; vi. 1880. 



