388 



SPINY-FINNED GROUP. 



shades of blue, purple, and rich orange." These voracious fishes feed chiefly on 

 the fry of other species. In the Arctic lump-sucker (C. spinosus) there are large, 

 conical bony plates, surmounted with a spine, on the head and body of the adult. 

 In the allied Liparis the skin is naked, and more or less loose. 



The Gobies and Mud-Skippers, — Family Gobiidaz. 



The gobies and their allies differ from the preceding family in that there are 

 always distinct rays to the pelvic fins ; although in some cases the two fins may 

 be joined in the middle line. Elongated in form, the body may be either scaled 

 or naked ; and the teeth are generally small, but may have enlarged tusks among 



fresh -water goby (nat. size). 



them. The spinous portion of the dorsal (whether separate or continuous with 

 the soft dorsal) is always composed of flexible spines, and shorter than the soft 

 dorsal. The gill-opening is more or less narrowed, and there is usually no air- 

 bladder. This very extensive family comprises littoral fishes of small size and 

 carnivorous habits, a few of which have accustomed themselves to a fresh- water 

 life. It contains a large number of genera, some of which are extremely numerous 

 in species, as are the latter in individuals ; and their range includes the coast- 

 regions of all the temperate and tropical seas. Geologically, the group is com- 

 paratively ancient, true gobies dating from the middle Eocene of Monte Bolca, 

 while the extinct genus Chirothrix occurs in the Chalk of the Lebanon. 



Familiar to all in the person of the common British species 

 Gobius niger, the gobies form a very large genus, with a 



Gobies. 



