232 PROCEEDINOS OF THE NATIONAL MUSEUM. vol. xxvii. 



insertion well forward. PseudobranchifB present. Vertebrae numer- 

 ous, 30 to 50. Scapular arch normal; myodome developed; actinosts 

 large, partly intervening between coracoids; ribs sessile on the ver- 

 tebrge. Pyloric caeca usually in small number {-^ to 8) ; air bladder com- 

 monly wanting. Genera numerous, mostly of the rock pools and 

 shores of northern regions; many species found in fresh waters; some 

 of the salt-water species descending to great depths. Most of the 

 species are of small size and singular aspect, and none is valued as 

 food. The family is an extremely varied one, which can not readil}'^ 

 be thrown into subordinate groups. Almost every species has an 

 individuality of its own, and among the marine forms it is necessary 

 to recognize almost as many genera as species. It is impossible to 

 throw these small genera together into large groups. Of the various 

 forms, probalily the American genus Jordania is nearest the primitive 

 scaly stock, from which such forms as Zaniolepis and Oxylebius among 

 the Ilexagramimd^d are also descended. Fresh-water degeneration is 

 exemplified in Cottu^ and Uranidea and deep-water degeneration in 

 Zesticelus^ Cottunculus^ and Psychrolutes. 



A. Ventral fins well developed, the rays I, 2 to I, 5. 



B. Spinous dorsal evident, not concealed in the flesh nor indistinguishable from soft 

 part; head with spines or tubercles (except in rare cases), its bones not all hidden 

 in lax skin. 



C. Pectoral fins without free rays below, and not coalescent. 

 D. Ventral rays not I, 5; usually I, 3, sometimes I, 2 or I, 4. 

 E. Spinous dorsal shorter than soft part, of less than 13 spines. 



F. Hemilepidotin^. Body definitely more or less scaly above, the scales 

 sometimes arranged in bands or sometimes modified as bony jilates, 

 these usually placed along lateral line or at base of dorsal (skin naked 

 in Arfediellus). 



G. Last gill arch without slit behind it; gill membranes united, free from 

 the isthmus. 

 H. Vomer and palatines with teeth; ventral rays I, 2. 



/. Preopercular spine with 1 to 5 enlarged hooks or antler-like pro- 

 cesses above, besides the two on its bifid or emarginate tip. 

 /. Body with three series of bony plates, those of the upper and 



lower series strongly keeled Stlengis, 1. 



JJ. Body with a single row of rough plates along the side; head 



with conspicuous pores Schmidt ia, 2. 



II. Preopercular spine bifid or simple, without hooks or antler-like 

 processes above. 

 K. Vent .very close behind ventrals; supraoccipital cirrus very 



high; skin with small, rough plates Archistes, 3. 



KK. Vent well l)ehind ventrals ; supraorbital cirrus low or wanting. 

 L. Upper preopercular sjiine forked; a simple flap above eye; 



body covered with rough scales above Daruma, 4. 



LL. Upper preopercular spine simple, more or less hooked at tip. 

 M. Body covered above with small, rough plates, those on 

 lateral line larger; preopercle with four spines; preoper- 

 cular spine slightly hooked Ricuzenhts, 5. 



AOf. -Body entirely scaleless; preopercular spine strongly 

 hooked Artediellus, 6. 



