BKARDKI) COTTUS OH AUMED BULLHEAD. 



209 



orl)it. The jiiws ;ire ;inned witli extremelj' fine, coni- 

 cnl and straight teeth, witli the jioiuts somewhat re- 

 curved, and set in several irregular rows, thus turniiug 

 fairly In-oad hands (cards). Tlie two upper pharyngeal 

 cards are round, tlie two lower triangular, all four being 

 composed of very small teeth. The gill-openings of 

 average size. The preoperculum, the surface of which 

 is generally striated, is almost twice as high as l)road 

 (long), and at the h)wer ])osterior corner is furnished with 

 a spine, pointing in a backward direction and generally 

 recurved. The opcrcuhna is also striated in most cases, 

 is of small size and irregular, triangular form, with 

 its longest corner pointing downwards, and bears supe- 

 riorly a blunt, longitudinal ridge. The nostrils are 

 arranged as in the preceding species, and here too, the 

 posterior one on each side is so small that it is to be 

 distinguished only with difficulty. The eyes, which are 

 set high, are smallei' than in the preceding species, the 

 diameter being less than the least breadth of tlie inter- 

 orbital space. The distance between them and the tip 

 of the snout is less than that between them and the 

 gill-openings. We sometimes find round the iris a ring 

 of dermal tubercles, especially "well-develoj^ed and raised 

 in a conical shape on the lower part of its margin. 

 The superior margin of the orbit forms a raised, blunt 

 ridge, which is sharper and even furnished witli spines 

 during \()uth. From this ridge run two bars, diverging 

 posteriorly, the inner of which ends in a protuberance 

 corresponding to the ordinary occipital spine of the 

 Cotti, while the outer runs across the squamosal bone 

 and ends in an obtuse spine, at the hind point of the 

 posttemporal bone. The suborbital bones are elongated; 

 the lower part of the anterior one is furnished with 

 three transverse ridges, with depressions between them 

 wliich contain the mucifei'ous cavities and pores be- 

 longing to the system of the lateral line; and the 

 posterior, which is larger and is united to the pre- 

 operculum, is square in form and has a bony spine, 

 pointing in a backward direction, at the middle of the 

 raised lower margin. The spines of the head are thus 

 8 in number — four on the tip of the snout and two 

 on eadi side of the head, the anterior on the suborbital 

 bone and the posterior on the preoperculum. On the 

 head we also find a number of short barbels, which 

 ai'e characteristic of this species, and the arrangement 

 of which is given in the specific description. 



The bod)' is covered with plate-like scales, furnished 

 with an edge or compressed elevation, Avhich in most 

 cases, at least among young specimens, ends in a more 

 or less sharp point, which extends back over the margin 

 of the next scale. Tliese plates are set in regular rows, 

 which form longitudinal ridges or edges. The back 

 and a ])art of the sides are covered by two rows, the 

 plates of wliich, especially the anterior by the occiput, 

 arc lav'cr than those of tlie othfsr rows, and the antei*ior 

 ones, especially in old siiccinicns. without any spine. 

 These two rows, each of whicli is made up of about 

 20 plates — four of ^\■hich lie in front of the first 

 dorsal fin, two, one or none between the two dorsal 

 fins, and seven or eight along the base of the second 

 dorsal fin — form a furrow along the back, are broad 

 anteriorly, and gradually decrease in breadth towards 

 the second dorsal fin, at the end of which, when it is 

 depressed, they unite and from this point to the base 

 of the caudal fin form only one row, containing about 

 12 plates". Under the belly there are two rows, with 

 about 20 plates in each, and in extent and position 

 analogous to those on the back. They unite at the 

 end of the anal fin, forming from this point to the root 

 of the caudal fin a simple row of 12 plates. This 

 union of the rows of plates, botli on the back and on 

 the belly, renders the anterior part of the bod)- octa- 

 gonal, the posterior hexagonal. Between the rows de- 

 scribed there are two others, parallel to them, on each 

 side of the bodv; the upper consists of about 27 plates, 

 begins at the end of the pectoral fin, and extends in 

 a straight line from this point to the base of the caudal 

 fin; the lower begins at the insertion of the pectoral 

 fin, consists of about 34 plates, and also ends at the 

 base of the caudal fin. Besides these regular rows of 

 plates, there are other smaller, convex, rounded plates, 

 on some parts of the body, e. g. in front of the pec- 

 toral fins and round the vent. The lateral line, the 

 scales of which, like the plates, gi-adually diminish in 

 size as they approach the caudal fin, runs along the 

 middle of the body, rises slightly above the pectoral 

 fins, and from the end of these fins runs in a straight 

 line to the caudal fin. The vent lies well in front, 

 at the end of the first quarter of the length of the 



body. 



The first dorsal fin is almost triangular, with 

 I'ounded apex, and contains five or six simple rajs, the 



" The number varies between 9 and 13; on the anterior ones the top of the ridge is longitudinally divided. 

 Scandinavian Fishes. 



