464 GEOGRAPHICAL ZOOLOGY. [part iv. 



Family 115.— MYXINID^. (2 Genera, 5 Species.) 



" Marine eel-like fishes, with four pairs of barbels." 



Distribution. — Seas of the temperate regions of both hemi- 

 spheres. 



Sub-class VL— LEPTOCAEDIL 



Family 116.— CIRRHOSTOMI. (1 Genus, 1 Species.) 



" A small marine fish with no jaws or fins, and with rudi- 

 mentary eyes." 



Distribution. — The only species, the Lancelet (AtnpJiioxus)^ 

 is the lowest form of living vertebrate. It is found in the tem- 

 perate regions of both hemispheres, and has occurred on our 

 southern coast. 



Remarks on tlie Distribution of Fishes, 



Marine Fish. — There are about 80 families of marine fishes, 

 and of these no less than 50 are universally, or almost uni- 

 versally, distributed over the seas and oceans of the globe. Of 

 the remainder many are widely distriljuted, some species even 

 ranging from the North Atlantic to Australia. Six families are 

 confined to the Northern Seas, but four of these consist of single 

 species only, the other two being the Discoboli (2 genera, 

 11 sp.), and the Accipenseridas (2 genera and 20 sp.). Only one 

 family (Acanthoclinidffi) is confined to the Southern oceans, and 

 that consists of but a single species. Four families (Sternop- 

 tychida^), Stomiatidte, Alepocephalidae and Halosauridaj) are 

 confined to the Atlantic Ocean, while 13 are found only in the 

 Pacific ; and of the remainder several are more abundant in the 

 Pacific than the Atlantic. Two families (Lycodidre and Gadida?) 

 are found in the Arctic and Antarctic seas only, though the 



