CEP 



[78] 



C E R 



having the bones united into one 

 osseous case : in form, this fish 

 hears a resemblance to the elonga- 

 ted trilobites of the transition rocks. 

 Of the genus cephalaspis Agassiz 

 established four species, namely, 

 C. Lyellii, C. rostratus, C. Lewissii, 

 and C. Lloydii. Of these four 

 species, the first is found most 

 abundantly in the red sandstone, 

 both of England and Scotland, 

 and is constituted the type of the 

 genus. An entire fish of the ce- 

 phalaspis Lyellii has been found in 

 the old red sandstone of Forfar- 

 shire, the head of this fish is very 

 large in proportion to the body, 

 and occupies very nearly one- 

 third of its whole length. The 

 outline is rounded, in the form of 

 a crescent, the lateral horns in- 

 clining slightly towards each other, 

 while the anterior and central 

 parts project much. The middle 

 of the head, including the region 

 of the eyes, the cranium, and the 

 occipital crest, is elevated, whilst 

 the sides and anterior edge are 

 considerably dilated and horizon- 

 tally extended. The eyes are 

 placed in the middle of the shield 

 and near each other, but a little 

 nearer to the end of the snout than 

 the occipital crest ; they appear to 

 have been directed straight up- 

 wards. The posterior and middle 

 portion of the head is nearly square, 

 and is edged by the first series of 

 scales. The C. Lloydii has a head 

 the least resembling that of a fish, 

 it occurs in the cornstone of Shrop- 

 shire, Worcestershire, Hereford- 

 shire, &c. Cephalaspis appears to 

 have formed the connecting link 

 between crustaceans and fishes ; 

 no existence of the present creation 

 at all resembles the cephalaspis. 

 CEPHALOPHOHA. The first class of the 

 sub-kingdom Mullusca. This class 

 has usually been called Cephalopo- 

 da, but, according to the classifica- 

 tion of Pictet, it is now divided 



into six orders, namely, Dibran- 

 chiata, Tetrabranchiata, Pulmonata, 

 Pteropoda, Gasteropoda Dicecia, 

 aud Gasteropoda, Monoecia. 

 CEPHA'LOPOD. \ (from /ce0a\r}, head, 

 CEPHALOPODA. > and iro&es, feet, 

 CEPHALO'PODES. ) Gr.) A term 

 applied by Cuvier to a large family 

 of molluscous animals, from their 

 having the feet placed around their 

 heads, and walking with their heads 

 downwards. The feet are lined 

 internally with ranges of horny 

 cups, or suckers, by which the 

 animal seizes on its prey, and 

 adheres to extraneous bodies. The 

 mouth, both in form and substance, 

 resembles a parrot's beak, and is 

 surrounded by the feet. It is now 

 well established that the living 

 species of cephalopods which 

 possess no external shell, are pro- 

 tected from their enemies by a 

 peculiar internal provision, consist- 

 ing of a bladder- shaped sac, 

 containing a black and viscid fluid, 

 or ink, the ejection of which, by 

 rendering the surrounding water 

 opaque, conceals and defends them. 

 The sepia vulgaris and loligo afford 

 us familiar examples. Buckland. 

 According to Prof. Phillips, the 

 following are the genera of Cepha- 

 lopoda : Bellerophon, Orthoceras, 

 Belemnite, Nautilus, Ammonite, 

 Edomite, Scaphite, Baculite, Num- 

 mulite. The only living species 

 belong to the genus Nautilus, of 

 which there are two. 



The Cephalopoda, in the arrange- 

 ment of Cuvier, form the first class 

 mollusca, and comprise the follow- 

 ing genera, which he divided 

 according to the nature of the shell, 

 Sepia, Nautilus, Belemnites, Am- 

 monites, and Nummulites. 

 CEBAU'NII LA'PIDES. (from Kepawos, 

 Gr.) A name formerly given to 

 fossil echinites, from a supposition 

 that they were formed in the air. 

 CERATOPHI'TA. In Linnseus's ar- 

 rangement, an order, the 6th, of 



