476 PISCES SUB-CLASS IILTELEOSTOMI. 



distinguish the gurnards ; which are further characterised by their great 

 ugly, bony heads, and the brilliant hues of scarlet or blue with which 

 many of them are adorned. They inhabit all temperate and tropical seas, 

 and are predacious fish, living chiefly on crustaceans. Their habitat is the 

 sea-bottom, on which they crawl by means of the elongated pectoral rays ; 

 those appendages apparently also acting the part of feelers. When seen 

 crawling on the bed of a glass tank in an aquarium a gurnard presents a 

 peculiarly ghost- like appearance, reminding the beholder of some monster in 

 a pantomime. 



Nearly allied to the last is the family typified by the flying-gurnards 

 (Dactylopterus), which rival the true flying-fish in their power of skimming 



over the surface of the waves by means of their greatly ex- 

 Family panded pectoral fins. All are easily recognised by the in- 

 Dactylopteridce. vestiture of the body in a complete cuirass of keeled bony 



plates or scales. In Britain the group is represented by the 

 so-called armed bull-head, which belongs to the genus Agonus ; and the 

 family also includes the beaked-gurnards, distinguished by the prolongation 

 of some of the bones of the skull in the form of a flattened process on each 

 side of the snout. The flying-gurnards themselves inhabit the Mediterranean 

 and tropical seas. Here, too, may be placed the curious little dragon-fishes 

 (Pegasus), which inhabit the seas of Australia, China, and India, and have a 

 long beak and the body protected by very large plates ; the coloration taking 

 the form of small dark spots. 



Very different in appearance to the last are the clumsy-looking fishes 

 known as lump-suckers (Cydopterus), which are the typical members of a 



family belonging to another sectional group. In this section 



Section Gobii- the dorsal fin may be single or double, but its spinous 



formes. Family division or portion is always short, and may consist of 



CydopteridcK. flexible spines ; the soft dorsal being equal in extent to the 



anal. There is no bony connection between the preopercular 

 and the suborbital ring ; but there is a prominent papilla in the region of 

 the vent. When pelvic fins are retained, they usually comprise a spine and 

 five rays, although exceptionally the number of the latter may be reduced to 

 four. In addition to their clumsy build, the lump-suckers are distinguished 

 as a family by the presence of a sucker on the lower surface of the body sup- 

 ported by the rudiments of the pelvic fins. By means of their sucker these 

 fishes affix themselves firmly to rocks or stones, and are thus safe from the 

 buffeting of the waves. There are two generic modifications of the family, 

 namely Cydopterus and Liparis, in the former of which the skin is tuber- 

 culated and viscous, whereas in the latter it is entirely bare. All the 

 members of the family are confined to the colder northern seas, some of 

 them even entering the Arctic Ocean. 



From the lump-suckers, the gobies (Gobius) and their allies the mud- 

 skippers (Periopthalmus) are sufficiently distinguished by the presence of 



well-developed rays to the pelvic fins, which may, however, 

 Family be united together in the middle line of the body. The group 



GobiidcB. is a very extensive one, both in respect to genera, species, 



and individuals ; and it is represented on the temperate and 

 tropical coasts of all parts of the globe. It is, of course, impossible to char- 

 acterise the various genera ; and, as regards the gobies, it must suffic3 to say 

 that they are small fishes with a geographical range as extensive as is that 

 of the family, and that, in many cases, the males build a cleverly constructed 



