NATURAL SCIENCES OP PHILADELPHIA. 13 



Notice of a New Species of HEMILEPIDOTUS, and Remarks on the Group (TEM- 

 NISTIiE) of which it is a member. 



BY THEODORE GILL. 



In the family of Cottoids there exist three genera which quite closely re- 

 semble each and have a rather peculiar physiognomy, but at the same time 

 differ so decidedly from each other, and are distinguished by characters of 

 such previously acknowledged importance, that their close mutual affinity has 

 been overlooked ; and the respective genera have been referred to the neigh- 

 borhood of quite dissimilar groups.* The best and largest known of these 

 genera is Hemilepidotus of Cuvier ; the other two are Temnistia of Richardson 

 and Scorpcenichthys of Girard. For the group thus composed, the name of 

 Temnistice is preferable, as it describes the most peculiar character of the 

 group. Although Hemilepidotus is the chief genus, its name is too restrictive 

 to be modified for the appellation of the group. 



The Temnistice are distinguished by the development of the first dorsal fin, 

 which is more than half as long as the second, composed of about eleven 

 spines, and with the anterior spines rather shorter and more or less separated by a 

 notch or incision from the following. The supramaxillary bones, snout, supra- 

 orbital region and the forehead and preorbital bones are furnished with cuta- 

 neous tags or barbels. 



The three genera are chiefly distinguished by the following differential cha- 

 racters. 



Temnistia Richardson. 

 Abdomen nearly hemispherical and naked. Pectinated scales cover the rest of 

 the trunk. Second dorsal and anal Jins with undivided rays. 



Hemilepidotus Cuvier. 

 Scales in two longitudinal bands on each side, one dorsal and one lateral. 



Scorpcenichthys Girard. 

 Body naked and smooth. V. I. 5. 



Five species, inclusive of that here described, are now known to belong to 

 the group. All of them are peculiar to the western coast of North America or 

 the Arctic Seas ; the typical species of Hemilepidotus, as well as the single 

 known Temnistia, are both found in the Northern waters. The existence of 

 Temnistia has been quite forgotten by the recent systematic writers, although 

 its rank as a valid genus cannot be challenged. 



Hemilepidotus Gibbsii Gill. 



The form and proportions are nearly identical with those of H. spinosus 

 (Girard.) The crown, the region above the preoperculum and operculum, 

 and the interocular space, are granulated, but without spines. There are four 

 equidistant short flaps in a transverse row behind the interorbital area, four 

 papillose barbels on the margin of each preorbital bone, and another on the 

 suborbital above the end of the supramaxillary ; from the centre of the latter 

 a larger compressed flap springs. On the chin are four small flaps. A flap 

 also exists near the anterior angle of the upper cleft of the branchial aperture. 



* I embrace this opportunity to state that the genus Triglopsis of Girard is most closely 

 allied to my Oncocotlus, of which the Cottus quadricornis of Europe is the type, and 

 differs chiefly in the absence of the " horns " or claviform tubercles and in its fresh water 

 habitat, &c. The entire family of Cottoids indeed requires a careful revision. Dr. 

 Giinther has been quite unsuccessful in his distribution of the species, and has regarded 

 as doubtful, species which belong to peculiar genera that have been clearly and distinctly 

 characterized, while genera and species whose claims to that rank are much more ques- 

 tionable have been admitted. 



1862.] 



