290 



NORTHERN ZOOLOGY. 



a little slip at its posterior end higher than the portion immediately preceding it. The ven- 

 trals, second dorsal, and anal are small, and the two latter have each a posterior slip, taller in 

 proportion than that of the first dorsal. The origin of the second dorsal corresponds with the 

 end of the anal. The ventral appendages are semicylindrical, covered with the common in- 

 teguments exteriorly, and terminated hy a minute, hard, callous tip. The tail at the origin of 

 the caudal inclines a very little upwards. The anterior under lohe of the caudal is as high, 

 but not so wide, as the first dorsal : it is connected by an even fillet of fin about twice as long 

 as itself, to the second lobe, which uniting with the upper portion of the caudal forms an 

 oblong lanceolate tip to the tail; the upper half of the caudal is widest at the extremity, and 

 gradually becomes lower as it runs forwards, being no longer perceptible a little posterior to 

 the commencement of the under part of the fin. 



Skin. — The whole exterior of the fish, including the fins, feels rough when rubbed towards 

 the snout. On examining a portion of the skin with a powerful microscope, it is observed to be 

 completely encrusted by a congeries of small, hard, transparent, lancet-shaped, tricuspid 

 spines or scales imbedded in a fibrous matter. The roughness extends to the anterior half of 

 the tongue and palate, and to portions of the branchial arches. There are several rows of 

 minute pores on the head, particularly on the cheeks and at the angles of the mouth. Two 

 pores larger than the others, but not capable of admitting the point of an ordinary-sized pin, 

 exist on the hind part of the head, one on each side of the mesial line. There are no traces 

 of spiracles near the eyes. 



Teeth. — There are four rows of teeth in each jaw, having the form of very oblique spherical 

 triangles, the posterior side much the shortest, and the acute point directed towards the 

 corners of the mouth, and overhanging a small rounded lobe of the base. The edges of the 

 teeth are very acute, but even under a good lens do not appear dentated or serrated, though a 

 slight inequality, approaching to crenature, may be perceived with a high magnifying power. 

 There is scarcely any difference in the form of the teeth of the two jaws. 



Dimensions 



Of a specimen kept in spirits. 



Inches. Lines. 

 12 9£ 



Length from tip of snout to extremity of tail 

 „ „ beginning of lower part of 



caudal 



end of second dorsal 



end of anal 



anus . 



end of first dorsal . 



beginning of ditto 



last gill-opening 



base of pectorals . 



foremost gill-opening 



nape . 



angles of mouth 



middle of upper lip 



centre of eye . 



nostrils 



Gape of mouth longitudinally . 



„ transversely (from corner to corner) 



9 Length of pectorals . . 



8 Spread of ditto 



7 8 Height of dorsal 



G Length of its attachment 



5 „ ventrals 



4 „ ventral appendages, interiorly 



2 9| „ attachment of anal 



2 81 Height of anal .... 



2 21 Length of attachment of second dorsal 



1 9 J Height of anterior, under caudal lobe 



1 94 Length of second lobe 



1 1 Distance between the lobes . . 



1 3 Total length of caudal fin beneath 



8 „ ,, above 



Inches. 



Lines 



. 2 



2 



rner) 

 1 



91 



8 



1 







1 



1 



1 



0i 







5 



r • ° 







7* 

 6 



. 

 



4 







11 







10 



1 



9 



3 

 . 3 



9* 

 6* 



