FIFTEEN-SI'INKI) .STICKLEBACK. 89 



SO that the tail remained hanging out of the mouth ; and it 

 was obliged at last to disgorge the eel partly digested. It 

 also seized from the surface a moth that fell on the water, 

 but threw up the wings. The effect of the passions on the 

 colour of the skin in the species of the genus Gasterosteus is 

 remarkable ;* and the specimen now spoken of, under the 

 influence of ten-or, from a dark olive with golden sides, 

 changed to pale for eighteen hours, when it as suddenly 

 regained its former tints. It spawns in spring ; and the 

 young, not half an inch in length, are seen in considerable 

 numbers at the margin of the sea in summer." — CoucJCs MS. 

 The whole length of this species is from five to seven 

 inches. The jaws are elongated, the under one the most ; 

 the mouth small ; the eye placed half-way between the point 

 of the nose and the end of the gill-cover ; the irides silvery, 

 the pupil black ; the head flat : the form of the body pentan- 

 gular, the tail depressed ; the lateral line marked by a series 

 of carinated scales throughout its whole length. The fin- 

 rays are : — 



D. XV -f 6 : P. 10 : V. 2 : A. 1 -f- 7 : C. 12. 



The fifteen dorsal spines, curved backwards, are each fur- 

 nished with its little membrane, and the last spine is the 

 longest and most curved ; the belly, with two elongated bony 

 plates, having, about midway on their inner edges, two un- 

 equally-sized ventral spines : the colour of the upper part of 

 the head, body, and tail, is greenish brown, the sides inclin- 

 ing to yellow ; silvery Avhite on the cheeks, gill-covers, under 

 part of the head, and belly ; the dorsal and anal fins have each 

 a black spot on the anterior part. 



* See Magazine of Natural History, vol. iii. p. 329. 



