56 SHOULDER-GIRDLE AND BREAST-BONE. 



scapula and the coracoid lie in the same plane, and the soft end of the coracoid reaches nearer 

 the abdominal line than the clavicle. But inside the junction of the scapula and coracoid there 

 is a mass of cartilage, which sends a long and stoutish cms forwards and upwards, so as to be 

 attached to the inner ridge of the clavicle, near its middle (fig. 8). This bar is ossified, save at 

 its ends, in the same manner as the scapula and coracoid, namely, by " ectostosis ;" it is the pra- 

 coracoid, which in nearly all the examples hitherto given has been ossified continuously with the 

 coracoid proper. This element figures greatly in the Amphibia, as an ectosteal bone ; but never 

 afterwards, as far as I know, as it is soon subjected to morphological degradation ; and although 

 it often reappears, it is always as a late-ossifying endosteal bar. If we compare the brachials of 

 the Trout with those of the Pike, we shall see that Nature has " changed hands," and that these 

 rays, which are like small drumsticks, increase in size from above downwards (see figs. 7 and 8, 

 b. 1 4) ; they are soft at each end, and the lowermost has a small periosteal wing. 



I shall omit the Cyprinidae, for although they differ from the Salmonida3 so much in 

 the character of their bones, which are as remarkable for density and strength as the others are for 

 extreme thinness and friability, yet, morphologically, there is very little difference between them. 



Fam. "CLUFEiDjE." 

 Example. Clupea liarengus, Linn. 



Here we have the same kind of Shoulder-girdle as in the two last-mentioned families ; but 

 there are some curious differences, and there is a gentle but evident descent in these Fishes 

 towards the true Ganoids. All through its skeleton, the Herring shows how little it has been 

 subjected to the severe numerical laws that affect the typical Fish ; yet it is most instructive, that 

 what is excessive for an ichthyic type, is the true number for some higher type. This is well 

 seen in the face, for few Fishes possess a malar or jugal; but the Herring has this bone, 

 and a " septo-maxillary >;1 as well : this condition is the rule in the true Reptilia. So for 

 vertical division of the arm-plate ; it occurs in the Ganoids, even amongst the recent ones, as 

 Polypterus and Calamoichthys ; but the Herring is the only Teleostean in which I have discovered 

 this second series. The splint-bones are fibrous, but tough and strong ; they are smooth, dia- 

 phanous, concentrically marked, and correspond exactly to the overlapped part of the " cycloid" 

 scales of the same Fish. The post-temporal (fig. 6, p. t.) has a large thin body, with a long 

 bony mucous tube on it ; its spurs are long and arcuate ; below, it overlaps the supra-clavicle. 

 This latter bone (s. cl.) is long, has a strong principal part, broader at the top than below ; 

 behind the base of the overlapping supra-temporal it gives off a semicircular plate, the exact 

 counterpart of the hidden portion of the ordinary cycloid scales of this Fish. The clavicle (cl.) is 

 much like that of the Trout, for the antero-internal wing looks inwards and forwards ; the antero- 

 external plate lies under the skin of the Fish's side. The posterior lamina of the clavicle is only 

 developed below, for the true Shoulder-girdle has, here, the same low position as in the Trout. 

 The lower part of the clavicle is hooked backwards, as in the Opah-fish ; and above this part it 



1 This term is new to science, and is now being used by me in a paper on the " Osteology 

 of the Kagu " (Rhinochetus) ; I consider it to be the fore-runner of the so-called "turbinal" of the 

 Lizard the "pre-vomer" of my former papers. 



