170 ACANTHOPTERYGII. 



Length of head 4f to 4§, of caudal fin 6 to Q\, height of body Q\ to 1\ 

 in the total length. Eye — diameter 1/4 of the length of the head, 1 diameter 

 from the end of the snont : the interorbital space is about 1/2 a diameter of 

 the eye in width except in the breeding males when it is twice that width. 

 The body, except during the breeding season when the male becomes more 

 plump (see Breeding, below), is elongated and compressed, with the vent about 

 midway between the hind edge of the eye and end of the caudal fin. Mouth 

 oblique, the posterior extremity of the maxilla reaching to beneath the middle of 

 the eye. Numerous rows of glands pass over the cheeks. The jaws of the male 

 augment in size and become more oblique during the breeding season. Teeth — 

 similar in both sexes prior to the breeding season in a single row of 20 to 25 

 minute ones placed close together : in the males they are replaced at this period 

 by a row of long pointed and rather widely separated ones, both sets may be 

 visible a short time in the same example ; in the mandible there are three or four on 

 each side, while below and inside the last of these teeth there is a recurved 

 canine : in the upper jaw there are about five of these long teeth on each side, and 

 inside the row on each side a recurved canine. Fins — First dorsal highest in 

 males, in which it is rather above two-thirds the height of the body below it : an 

 interspace exists between the two dorsal fins : the second dorsal fin is rather 

 higher than the body in adults, while the last rays decrease considerably in height. 

 Anal similar to second dorsal. Caudal in females or young slightly emarginate, in 

 males square with the corners occasionally rounded or -the middle rays may 

 be even produced. Ventrals in adults extend almost or quite as far backwards as 

 the pectorals. Scales — cycloid, large, thin and deciduous, they are inserted into 

 obliqUe muscular impressions on the body. Colours — transparent or pale yellow 

 with a single row of yellowish-red points along the bases of the dorsal and anal 

 fins which are straw coloured. 



Varieties. — Parnell's descriptions apply to males taken during the breeding 

 season, although he possessed both sexes, as Dr. Giinther supplied three of them 

 to Professor Collett, one of which, was a typical female, L. stuvitzii. 



Name. — Nonnat, French. 



Habits. — They are free swimmers, going with moderate rapidity, not residing 

 at the bottom. They live in large shoals and are taken in fine-meshed nets 

 set in from one to fifteen fathoms. In the Adriatic they are in immense numbers 

 and sold as food. They are frequently perceived coming to the surface but cannot 

 regain the depths, being fatigued and unable to exercise sufficient compression 

 upon their distended air-bladders. Collett says that the food in those he examined 

 from Christiania Fjords, in both summer and winter, consisted chiefly of micro- 

 scopic Copepods and other small pelagic animals. The Copepods, Bias longiremis, 

 Lilljeb, Temora velox, Baird, together with the larvas of decapods (ILippolyte and 

 Faloemon) and Mollusks in their swimming stage, Gardium. 



Breeding. — Collett considers it probable that no specimen lives more than 

 one year, and the breeding season completed, dies without going through a second 

 spawning, consequently they are really annual vertebrates. In Christiania Fjord 

 they breed in the summer months, normally between the end of June and com- 

 mencement of August. Spawning over all disappear. Most of the young attain 

 their full size in December or January, no trace of adults is perceptible, and all 

 go through the following changes. Here I propose adverting to the different 

 appearances of this fish, as discriminated by Professor Collett, whether in the 

 breeding season or otherwise. Out of the breeding season, there is but little 

 difference in the appearance of the sexes, the teeth being small, of uniform size 

 and in a single row. The males if nearly mature have longer jaws, and more 

 thickened heads than the females, while external to the row of teeth described 

 is an outer series of rather larger conical ones : the anterior rays of the second 

 dorsal and anal are higher than the posterior ones : while the caudal is square 

 or slightly emarginate. Mature males have a plump body and broad interorbital 

 space, with a thickened head, and a single row of long pointed teeth : while the 

 second dorsal and anal fins have the anterior and posterior rays of about the 

 same height : caudal truncated or rounded. The females, if nearly mature, differ 



