r.Kl.-KISIlKS. 



1015 



of the lirst (posterior) ln|)Ui'al \nniv. A contiiiucd vv- 

 duc'tioli woiilil thus seem to ohtiiin here; and the di- 

 nlivccrcMl caudal tin of flic l*'cl, a character wliicli woidd 

 else he the toki'u of a Iciw degree of evolution, ratliei' 

 suo'gests a far advanced, retrogre^ssive nietaiiioi-phosis. 



Among the peculiarities that characterize the .skidl 

 (it the I'.el, the first to attract attention iire the coin- 

 ]);n"iti\'el\- great expansion of the parietal bones (fig. 

 2i)H. jKir), wiiich form almost half the roof of the cra- 

 nial ca\itv, and the ext-essively cdongated S(|uamosal 

 hones (sijii). which li\ means of a long jirocess on the 

 upper side of the skull extend forward to a line with 

 the hind extremities of the upper ethmoids (ef and etr), 

 niui at aliout the middle of their length support the 

 pnstfrontals (splio). The last-mentioned bones rest below 

 on the jx'trosals {])tr), and have lost their imjiortance 

 as a p<iint of suspension for the hind extremity of 

 the suborbital ring. This {soJ/ — poh), which in our 

 common Hel — as \vell as fhe prefrontals (its anterior 

 suspensories) and turl>inals (sjiet) ■ — is cartilaginous, is 

 attached behind on each side of fhe skull to a process 

 (/)• in D), broken up into spines and originating from 

 the side of each frontal bone just before the anterior 

 cxtremitA' of the squamosal bone. The breaking-up of 

 this process into spines, wherebA' firmer muscular at- 

 tachments are secured, and which we h;ne previously 

 seen in the upper spinous processes of tlie anterior 

 abdominal vertebrtt, extends to the lateral occipitals 

 {lo) and the sipiamosals, that expand backwards like 

 wings, and, as well as the other bones in the lateral 

 walls of the skull, are characterized by a spongy tex- 

 ture. Thert' is no orbito-muscular canal; and the true 

 sphenoid (basisphenoideum, hsp in tig. 282) is closely 

 super[)osed on the parasphenoid, with upward processes 

 towards the descending processes (fr below in fig. 268, 

 (') of the frontal bones and towards the aiisphenoids 

 (alsji) beliind them. There are no ovbitosphenoid bones. 



(ireat diversity of opinion still prevails as to the 

 composition of the palatine and maxillary arches — as- 

 suming tliat both these arches should really be re- 

 garded as distinct in the present series. In that case 

 each of them consists on each side of only a single 

 bone. The inner bone (tig. 269, jjt), in the common 

 Eel of a thin and oblong, lanceolate form, often im- 

 perfectly ossitied in front, joins the oblique hyoman- 

 dibular {Inn) and the quadrate (fjii) to the anterior 



Zeitschr. Ges. Naturw. 1867. p. 270, laf. I, tig. 1 («)• 

 nilhinehn Fishes. 



part of the parasplmnoid (lig. 268, /isp). In the Con- 

 ger it is expanded anil liilid behind, one liraneh meeting 

 the h\<iniandibular, and the other forming the con- 

 nexion with the (piadrate. The outer bone (fig. 269, 

 iiiji) lies anteriorh' and thrcjughout the greater part of 

 its length ill the same plane as the inner, and is there 

 uniled 1)\ liganK'Uts witli the latter, the two bones thus 

 forming on each sid(! a ])alatine roof continuous with 

 the parasphenoiil bone. But the hind extremity of the 

 outer bone is twisted anil bent downwards, and is folded 

 outside the mandible, being united b)' strong, but loose 

 bands of sinew to the outside of the coronoid process 

 of the latter. In tiie common Eel this end is pointed, 

 in the Conger flattened, somewhat expanded, and in- 

 serted between the outer and inner Ijands of sinew by 

 which the great cheek-muscles are attached to the man- 

 dible. In the latter species the hind extremity of the 

 outer bone also glides on the outside of the coronoid 

 j)rocess of the lower jaw, by means of a flat and car- 

 tilaginous, articulary surface on each bone. In the Mu- 

 rivna, according to Jacoi5y", it is joined by a special 

 band of sinew to the outside of the quadrate. The an- 

 terior extremity of the (juter bone is tightly articulated 

 with the compound bone formed by the coalescence of 

 the vomer and the ethmoid (tig. 268, ef, etr, and r), 

 a striking resemblance to the corresponding connexion 

 between the intermaxillaries in the Pike, where we 

 found the said Ixmes (fig. 2.53, j/ma") similarly furnished 

 with a fiat, ascending process. But here these processes 

 (fig. 268, A) are so closely applied to the constricted 

 and carinated anterior (!xtremity of the ethmoid that 

 the}' almost meet above, behind the expanded head of 

 the vomer {etv, to the right in B). This connexion 

 reminds us most of the ordinary position in the Teleosts 

 of the palatine bones. Tlu' analogy between the outer 

 bone and a palatine is further strengthened by the 

 disposition of the teeth. In most of the fishes we have 

 hitherto seen fiu-nished with teetli both on the vomer 

 and the palatines, the transverse row of teeth on the 

 anterior extremity of the first-mentioned bone (the 

 head of the v(jmer) forms an arch together with the 

 palatine teeth, and iierc too the teeth are so arranged. 

 The long and narrow vomer (r), the posterior end of 

 which extends on the under side of the parasphenoid 

 bone a little beyond the orbits in the common Eel, is 

 armed underneath and in front, for rather more than 



128 



