THE FOUR-SPINED STICKLEBACK. 197 



at the base of the first ray of the anal fin, a small curved spine. Co- 

 lour of the head, back, and sides, brownish-green ; cheeks thorax, 

 and abdomen, silvery- white. Number of fin rays — 

 D. 9 ; P. 9 ; A. 8 ; C. 12 ; Branchial rays 3. 



Dr Stark was the first naturalist who noticed a four-spined 

 species of stickleback, inhabiting the waters of Britain ; seve- 

 ral specimens, about an inch and a quarter in length, were 

 found by him in a ditch in the neighbourhood of Edinburgh, 

 and exhibited at a meeting of the Wernerian Natural His- 

 tory Society in 1831. Since then I have met with it in 

 several localities ; in a stream about a mile above South 

 Queensferry ; in ditches at Guillon Links; in a ditch on the 

 west side of Duddingston Loch, and in the neighbourhood 

 of Berwick-upon-Tweed. In this last-named locality I 

 found three specimens with the third spine much shorter 

 than the fourth, which deserves to rank higher than as a mere 

 variety. (See Plate XXV.) 



Gasterosteus pungitius.* — The Tkn-spined 

 Stickleback. 



Specific Characters. — Back armed with ten spines. (Plate XXVI.) 

 Description. — From a specimen one inch and a half in length. 

 Body rather elongated, of an oval form ; sides compressed, naked, 

 without lateral plates ; operculum, preoperculum, and scapular plate, 

 rounded at the posterior margin ; eyes large ; under jaw the long- 

 est. Colour of the head, back, and sides, of a yellowish-brown, oc- 

 casionally dark brown, and in a few instances nearly black ; cheeks, 

 thorax, and abdomen, dull white, minutely frecked with dark olive, 

 liable to great variation in colour. Back with ten spines, the first 

 placed over the middle of the shoulder plate, the last, which is the 

 longest and stoutest, placed in a line over the anterior part of the 

 anal spine. Dorsal fin commencing close behind the last dorsal 

 spine, and ending in a line with the last ray of the anal fin ; its anterior 

 rays the longest, gradually decreasing from before backwards ; anal 

 fin corresponding with the dorsal : tail even at the end, or very 



* Guileroslcus puiif/ilius, Cuv., "Var., ,Feji., Don., Pen., Flem. 



