392 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



(ler. Dorsal spines minute, much shorter tLan pupil. Caudal pednncle 

 longer than head. Head 4; depth IG. D. XXV-9j A. I, 9; V. I, 5. 

 Pacific coast, from Monterey northward ; not rare. 



(Gill, Proc. Acad. Nat. Sci. Phila. 1861, 1(39: AuUscops spinescens Peters, Berlin Mo- 

 natsbericbt, IS'o'o ; Steind. Ichthyol, Beitr. v, 153.) 



Family LXIV.— GASTEROSTEID^. 



(The SticJcIebacJcs.) 



Body elongate, somewhat compressed, tapering behind to a slender 

 caudal peduncle. Head rather long, the anterior part not produced into 

 a tube. Mouth moderate, with the cleft oblique, the lower jaw promi- 

 nent. Teeth sharp, even, in a narrow baud in each jaw; no teeth on 

 vomer or j)alatines. Premaxillaries protractile. Preorbital rather 

 broad; suborbital jilate large, often covering the anterior part of the 

 cheeks, forming a connection with the preopercle. Branchiostegals 3. 

 Gill-membranes broadly joined, free from the isthmus, or not ; gill-rakers 

 moderate or rather long. Opercles unarmed. Skin naked or with ver- 

 tically oblong bony plates ; no true scales. Dorsal fin preceded by two 

 or more free spines ; anal similar to soft dorsal, with a single spine ; 

 ventral fins snbabdominal, consisting of a stout spine and a rudimentary 

 ray. Middle or sides of belly shielded by the innominate bones. Pec- 

 torals short, uuusnally far behind the gill-openings, preceded by a 

 quadrate naked area, which is covered with shining skin. Caudal tin 

 narrow, usually lunate. Air-bladder simple ; a lew pyloric coeca. Gen- 

 era 3, Gasterosteus, Apeltes, and Sinnachia. Species about 20. Small 

 fishes inhabiting the fresh waters and arms of the sea in Northern 

 Europe and America ; noted for their pugnacity. They are exceedingly 

 destructive to the spawn and fry of larger lishes 



" It is scarcely to be conceived what damage these little tishes do, and 

 how greatly detrimental they are to the increase of all the fishes among 

 which they live, for it is with the utmost industry, sagacity, and greedi- 

 ness that they seek out and destroy all the young fry that come their 

 way." {GUntker.) Most of the Sticklebacks build elaborate nests whicli 

 the male fish defends with much spirit. 

 { Gasterosteidw Guutlmr, i, 1-7.) 



a. Innomiuate bones joined, forming a triangular or lanceolate plate on the median 

 line of the abdomen Gastkijosteus, VXi. 



aa. Innominate bones widely separated, forming a bony ridge on each side, betwieu 

 which are the ventral tins Apeltls, 1'J4. 



