MANY-SPINED STICKLEBACK. 999 



quarrelsome, and in defeult of other game they destroy each other. The 

 males are more active than the females. In the breeding season the 

 males become jet black. In the spring this species, as well as all the 

 other specie^ of Stickleback, builds a nest for its eggs, and defends this 

 nest vigorously. 



Genus 88. PYGOSTEUS. Brevoort. 



Pygosteus (Brevoort, Mas ), Gill, Cat. Fishes East Coast, Proo. Ac. Nat. Soi., 1861 (not 



characterized) ; Can. Nat., Angust, p. 8 (reprint), 1865. 

 Gasterostea, Sauvagb, Nouv. Archive^ du Mns., Parip, 1872. 



T^pe, Gasterosteus oeddentalii, Cuv. and Val.^G. pungitius L. 



Etymology, puge, ruin[j ; osteon, bone. 



Body slender, elongate, somewhat compressed ; caudal peduncle very slender, with a 

 strong keel on each side, whiCh renders it much broader than deep ; skin destitute of 

 bony plates (except those connected with the pelvis) ; the plate extending upward from 

 the ventral fins well developed, striated ; head rather long ; the' mouth as in the other 

 species ; naked area in front of pectorals moderate ; backward processes from the 

 shoulder-girdle below well developed, widely divergent, forming a V shaped figure, em- 

 bracing a large naked space ; dorsal spines moderate, subcqnal, or the anterior ones 

 rather highest ; spines not set in a right line, diverging alternately to the right and left, 

 with more or less regularity ; spines 7 to 9 in number ; anal spine similar to the others ; 

 innominate bones rather feeble, joined more or less completely on the middle line of the 

 belly; ventral spines moderate, finely toothed; gill-membranes free from the isthmus 

 posteriorly. Perhaps but a single species widely distributed in northern regiops, in both 

 fresh and salt water. The group differs from Gasterosteus mainly in toe increased num- 

 ber of dorsal spines, and the greater freedom of the gill-membranes. It is probably un- 

 worthy of retention as a distinct genus. 



165. Pygosteus pungitius (L.) Gill. 

 Many-spined Stickleback. 



Gasterosteus pungitius, Linn.eus, Syst-Nat. 1758.— -Qunthbr, Cat. Fish., i, 6, Bban, Bull. 



U. S. Nat. Mus., XV, 1879, 129, and of most writers; 

 Gasterosteus concinfius, KiCHardson, Fauna Bor. Amer, 1836, .57.— Gunther, Cat. Fish., 



i,6. 

 Gasterosteus occidentalis, Cvv. and Val., Hist. desPoiss., iv, 1829, 509.— DeKay, New York 



Fauna Fishes, 68.— Gujstheb, i, 6. 

 Pygosteus pungitius. Gill, Mss. 



Gasteronteua mainensis, Storer, Bost. Journ., i, 464.— Gunthbr, i, 6. 

 Gasterosteus nebulosus, iGASSiz, Lake Superior, 1830. 

 Pygosteus nebulosus, Jordan, Man.-Vert., 1876. 



Pygosteus occidentalis, var. nei^losus, Jordan, Man. Vert , Ed. 1, 260. 

 Gasterosteus dekayi, Agassiz, Lake Superior, 1850, 311.— Stoebe, Hist. Fish. Mass. 

 Gasterostea pungitia, occidentalis and blanchardi, Sauvage, Nouv. Archiv. Mus. Paris, 1873. 

 DeseripKoji.— Olivaceous above, profusely punctulate; sides irregularly barred with 

 darker • belly silvery ; body very slender, somewhat compressed, tapering into the very 



