154 



Fam. 20. DISCOBOLI. 



Discoboli, pt., Cui\ Regne Anim. ; 3Iuller, Bed. Abhandl. 1844, p. 158. 



Body thick or oblong, naked or tubercular. Teeth small. One or 

 two dorsal fins ; the anal similarly developed as the soft dorsal. 

 Ventrals luith one spine and Jive rays, all being rudimentary, and 

 forming the bony centre of a round disk, ivhich is surrounded by a 

 cutaneous margin. Gill-openings narrow, the gill-membranes being 

 attached to the isthmus ; three gills and a half ; air-bladder none. 

 Pyloric appendages in great number. 



Carnivorous fishes, Uving at the bottom of the shores of the north- 

 ern seas. They are enabled to attach themselves very firmly to rocks, 

 &c., by means of the ventral disk. 



The family of Discoboli has hitherto comprised two very hetero- 

 geneous divisions of fishes. The present family is composed of those 

 only which are truly acanthopterous, which have the ventral disk 

 formed only by the ventral fins, the skeleton but slightly osseous, 

 and numerous pj-loric appendages. They differ, besides, from the 

 Gobiesocida' in a great many other points. They approach closely to 

 the Gobiidce, from which they are distinguished by the complete 

 transfoiTQation of the ventral fins into an adhesive organ, by the 

 numerous i^yloric appendages, &c. 



Synopsis of the Groups. 

 Two separate dorsal fins. Vertebrae 12/16 .... a. Cyclopterina. 



One dorsal fin. Infraorbital joined to the prse- 



operculum. Vertebrae 12/30 b. Liparidina. 



First Group. CYCLOPTERINA. 



Only one genus. 



1. CYCLOPTERUS. 



Cyclopterus, Artedi, Genera, p. 61 ; Cuv. B^gne Atiim. 



Body thick, more or less elevated ; skin viscous, tubercular. Head 

 large, snout short. Two dorsal fins, the anterior formed by flexible 

 spines. Ventral fins composed of one spine and five rays, all united 

 into a more or less circular disk. A villiform band of teeth in the 

 jaws, palate smooth. Three gills and a half, pseudobranchise ; bran- 

 chiostegals six. GiU-opening narrow, the gill-membranes being 

 united below the throat and fii-mly attached to the isthmus. Skeleton 

 but slightly osseous. Pyloric appendages numerous. 



Northern seas of both hemispheres. » 



