KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 40. NIO 5. 9? 



ChaBnichthys aceratus n. sp. 



1 specimen caught in a depth of 3-4 futhoms, Boiler Härbour, Uumberland Bay in Dec. 1.904 tem- 

 peraturs ot the water + 8 ° C. 1 ' , y ' 



Dorsal: VII, 37; Anal: 36; Pectoral : 25 (including a rudimentary upper ray). 



Total length • • • • . 522 mm. 



» » without candal r 4g5 



Depth of body at the beginning of first dorsal '.'.'. 91 » 



Length of head (including opercular flap) '.'.', 190 » 



Praorbital length of head 9 9 



Postoibital » » » -n 



Interorbital width (osseous) 35 s> 



Distance from orbit to nostril 21 » 



Longitndinal diameter of eye 32 » 



Greatest breadth of snout on a level with nostiils .... 77 » 



Distance from snout to flrst dorsal 190 (> 



» » » >> anal fin 265 » 



Length of pectoral 94 >> 



» » ventral 80 » 



Depth of caudal pednucle 22 » 



Length of raandible 127 >> 



>> » maxillary U5 >> 



Body naked provided with two lateral lines, the lower confined to caudal pe- 

 duncle. Head pickerel-shaped. Snout broadly rounded, spatulate, its greatest width 

 at a level with nostrils contained about 2V 3 times in a length of head. Head very 

 large, its length with the opercular flap is contained about 27, times in total length 

 including caudal, or constitutes 40,8 % of the total length without caudal. It is 

 scaleless and covered by a soft skin. The length of the prseorbital portion of the 

 head is almost equal to half the length of the head. The longitudinal diameter of 

 the eye is not contained quite fully 6 times, in the length of the head, and it is a 

 little less than the interorbital width of osseous parts. The latter measurement is 

 contained about 5V 2 times in length of head. A large and wide tubular nostril V 3 

 of the diameter of eye in front of the orbit. The supraorbital margin rises posteri- 

 orly to a low ridge which ends on a level with the posterior margin of the eye. 

 Behind the end of this ridge a low tubercle. Interorbital region concave and from 

 the same two ridges extend forward bordering a broad furrow on the snout, which, 

 however, not reaches to the end of the vomer which presents a slightly raised me- 

 dian ridge at the end of the furrow. There is no trace of a »horn» on the snout 

 (as in Ch. rhinoceratus). On the crown five low ridges radiate from a eommon centre, 

 one median straight backwards, one transversal on either side in a lateral direction 

 forming a right angle with the median one, and finally one obliquely backwards on 

 either side dividing the angle between the median and the lateral ridges. The 

 maxillary extends to below the posterior börder of eye. The lower jaw is a little 

 shorter than the upper. Broad bands of small pointed uniform teeth on both jaws. 



1 This was unusually high temperature, as product of a vvarm and sunny day, SÖblino says, the usual 

 temperature of the water was + 3,5 ° C. 



K. Sv. Vet. Akad. Hand]. Band 40. N:o 5. 13 



