468 DR JOHN ALEXANDER SMITH ON CALAMOICHTHYS, 



along its base, including the thickness of the bony spine itself, about -^ of an 

 inch. 



The Ventral jins are entirely wanting. 



The Anal fin is placed immediately behind the anal opening, and close to 

 the caudal extremity of the fish. Its base is marked by a loose flap or fold of 

 the skin along each side of the body, which is covered by a distinct series of large 

 oblong-shaped scales, some twelve or thirteen in number, laid side by side ; 

 and within this fold the closed fin lies as in a protecting case or sheath. 



At the anterior part of the base of the fin there is a somewhat triangularly- 

 shaped and thickened portion, the broad base of the triangle being next the 

 body, and its point extending upwards in a fleshy or membranous skin, along the 

 anterior margin of the fin; this triangular portion of the fin is covered by a 

 group of scales, a patch of smaller ones in the middle, being surrounded by a 

 row of larger scales outside. 



The fin-rays are hard, and are thirteen in number ; they consist of eight 

 large, broad, and pointed rays, each closely covered with a row of ganoid 

 scales ; and of five smaller fin-rays posteriorly, more thinly covered with scales ; 

 and a membranous edge or border of the fin extends beyond the rows of 

 small ganoid scales which cover each of the rays. You have, therefore, in 

 this fin, first, the triangular base, with its extension alongside and in front of 

 the fin-rays, then the group of eight large and strong fin-rays placed closely 

 together, and completely covered with closely-set ganoid scales, the first ray being 

 very large and broad ; and next to this there is the group of slender, softer, and 

 more separated or secondary rays, with their smaller rows of ganoid scales; the 

 membranous extension of the rays forming a soft border to the fin all around. 

 The length of the fin along its base is -§- of an inch, and the length of its fifth 

 or longest central fin-ray is also about f of an inch ; and its rays extend consider- 

 ably beyond the base of the caudal fin-rays. 



The Caudal extremity of the fish, from anus to extremity of caudal fin-rays, is 

 l^j inch in length ; it is therefore rather more than ^ of the total length of 

 the fish. It is much compressed laterally, and somewhat triangular in form ; 

 and the fin arising around its extremity is homocercal in character, at least in 

 its general contour ; the form of the tail being somewhat oval or rounded at its 

 distal extremity ; the fin-rays are large, strong, distinct, and covered with rows 

 of ganoid scales ; the anterior rays being shorter and somewhat fringe-like, espe- 

 cially above ; those next the centre divide at about the middle of their length into 

 two terminal rays, which again subdivide, and along which the ganoid scales are 

 continued in a smaller series, to their distal extremities. The rays are all con- 

 nected together by membrane, which is most distinct between the more separated 

 rays at the commencement of the fin, on the dorsal surface of the caudal 

 extremity. The fin-rays are thirteen or fourteen in number, the length of the 



