824 



EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



[78] 



that "the homologies of the elements of the girdle of Dipnoans with 

 those of other fishes, and the added elements in the latter will be as 

 follows " : 



POSTTEMPORAL ELEMENTS. 



posttempoeal. 



postteeotempoeal. 



Teleotemporals. 



Suprascapulaire. 

 Scapulaire. 

 Os coracoidien. 



Suprascapula 



Scapula. 



Clavicle. 



Sapraclaviculare (a). 

 Supraclavicalare (6). 

 Accessorisches Stiick. 



Posttemporal. 

 Supraolavicle. 

 Postclavicles. 



Among Teleosteans, as a rule, the posttemijoral, a forked bone (Plate 

 VIII, Figs. 23, 24 Pst. T.), has its inner limb resting on the epiotic, 

 and its outer one resting against or articulating with the pterotic. In 

 Bome fishes, as the Cats, this limb comes lower doAvu on the side of the 

 cranium. 



The posttemporal of Amia, although it has on side view (Fig. 24) very 

 much the appearance of this bone in Micropterus, this is by no means 

 the c^e on superior view. In the Ganoid the bone is much spread out 

 horizontally and sculptured for a narrow strip just within its external 

 border, like the "cover-bones" of the skull. Moreover, its inner limb, 

 in Amia, articulates with the epiotic, while its outer and lower one, a 

 rounded prong, meets, the opisthotic. 



The posttemporal in Micropterus is placed much more in the vertical 

 plane ; the anterior extremity of its somewhat compressed and longer 

 upper limb rests on the epiotic, while its lower and shorter limb abuts 

 against the pterotic. A process in both these fishes projects backwards 

 from this fork of the posttemporal, against the inner aspect of which 

 the posterotemporal articulates. This latter is a scale like element, with 

 rather a rounded superior head. Its posterior border is deeply notched 

 in Amia, and in both cases its flat surface is nearly parallel with the 

 median plane (Figs. 23 and 24, Fsto. T). Besting on the inner surface 

 of the lower fifth of the posterotemporal in Amia, we see the upj)er teleo- 

 temporal and the superior part of the vertical portion of the proscapula. 

 This arrangement is far different in Micropterus, where the teleotemporals 

 do not come in contact with the posterotemporals at all. The teleotem- 

 jporal of the Mudfish is of a quadrilateral outline, and this Ganoid is 

 without any lower teleotemporal (Fig. 23 T.). 



