1G2 



PISCES. 



a little in front of the transversely arched mouth. The skin is 

 rarely naked ; it is usually shagreen-like in consequence of the 

 osseous bodies which are embedded in it, or it may also be covered 

 with osseous plates and scutes. The palato-quadrate bax- is moveable 

 and is separate from the cartilaginous cranial capsule. 



Tribe 1. Squalides (Sharks). Spindle-shaped Plagiostomes, with 

 lateral gill slits ; eyelids with free edges ; incomplete shoulder girdle, 

 without cranial fin cartilages. 



The body is spindle-shaped, carries the pectoral fins more or less 

 vertically, and ends with a powerful tail, which is bent dorsalwards 

 at the end. There are, however, forms which, with regard to their 

 body shape, are allied to the Rays, and constitute forms of transition 

 to the latter group, e.g., the genus Squatina. The teeth are usually 

 pointed and dagger-shaped, and placed in numerous rows. The 



FIG. 606. Chimcera monstrotu (regne animal). 



families are distinguished principally by the number and position of 

 the fins, by the presence or absence of spiracles and of a nictitating 

 membrane, and also by the form and structure of the teeth. 



Fain. Scyllidse ( Dog-fishes). Scyllium canicula L., the coasts of Europe. 



Fam. Cestraciontidae. Ccntntcinn PJtilijtjn Blainv. 



Fam. Lamnidae (Porbeagles). Lainna ijlauca Mull., Henle ; Selaclie maxima 

 Gunn. , reaches a length of thirty-two feet. 



Fam. Carchariidae. Carclwu-ias i/lauciis Rond. the Blue Shark, with 

 umbilical placenta. C. lamia Risso. These two last are found in the Mediter- 

 ranean and the Ocean. Zi/fja-nn maUrua Risso. the Hammer-headed shark. 



Fam. Galeidae (Topes). Galen* runis Rond., European seas ; JfuxteJux rtili/arte 

 and laris Rond.. with umbilical placenta, both are found in the Mediterranean. 



Fam. Notidanidae. Xotidanits (Sexanehus) yrixens Gm. and .V. (Hrjitan- 

 i-hitx) cinereus Gm., Mediterranean and Ocean. 



Fam. Spinacidae (Spiny Dog-fishes). Aeantkias i-i/It/tir/x Risso (fig. 

 found from the northern seas to the South Sea. 



Fam. Squatinidae (Angel- or Monk-fishes). Sonatina rnh/ar : s Risso 

 squat inu L.) European seas. 



