Xli. EXPLANATION OF CATALOGUE. 



equal in size, and arranged in numerous rows like strij^s of velvet 

 (villiform) ; sometimes they are larger and in single or few I'ows, like 

 the teeth of a comb (cardiform). Some species have large compressed 

 fangs, some conical canines, while others have sharp cutting incisors 

 in front, or grinding molars behind, while a few have flat pavement-like 

 rows of teeth on the palate, or on the hinder parts of the jaws]. The 

 mode of attachment diiFei-s, they are seldom contained in sockes, but 

 are generally either united to the bones by ligament alone, or else are 

 coalescent vnih. them by ossification. Usually they are constantly 

 renewed when broken. 



"Fins. — The fins are in pai-t unpaired and situated in the plane that 

 di\T.des the body into two halves, in part paired, and lying on each side. 

 The last may be four in number, two pectoral fins placed behind the 

 gills, and two ventral fins situated more below. In some fishes these 

 last are placed quite forward in front of the pectoral fins (ventrals 

 jugular) ; in others they lie almost drrectly below the pectorals (ventrals 

 thoracic), and sometimes they lie nearer to the tail, behind the pectorals 

 (ventrals abdominal). The unpaired fin at the end of the tail is called 

 the catidal fin ; that which is attached to the body below the anal fin ; 

 and that which is situated above, upon the back, the dorsal fin. Any 

 of these fins may be divided into two or more portions. Adijyose fin 

 is the name given to a small dorsal fin without rays, which lies behind 

 the ordinary doreal fin. The small bones which support the fins, and 

 between which the membrane is extended are named rays. These are 

 either composed of joints {articulated), and often split at the point into 

 different branches {soft rays), or simple, hard, and pointed {spinous rays). 

 Wlien these last are present they are situated at the fore part of the 

 dorsal, anal, or ventral fins. The number of rays is used as a specific 

 character. The ventral fins are situated in front of the vent, while the 

 anal fin begins behind it, bvit in some fishes the vent is placed far forward, 

 close under the head. 



" The lips, jaws, and head have often filamentous appendages 

 {tentacles) ; when xinder the chin they are called barbels. 



"The number of vertebrce, of which the spine is composed, varies 

 very much, from seventeen to more than one hundred. The tail is formed 

 by nearly the half, and often by many more than the half, of these 

 vertebrae." 



F. W. HUTTOK 



Colonial Museum, 



December, 1871. 



