LAWYER. 997 



only ; interclavioles developed. There are also several important peculiarities in the 

 shoulder girdle and sknll, which separate these fishes from the perch-like forms. The 

 name hemi, half; bragchia, gills) alludes to. the reduction in number of the branchihyals. 



Analysis of Families of Hemibbanchii. 



a. Bones of head moderately produced; ventral fins of a stout spine and a rudimen- 

 tary ray ; dorsal fins preceded by free spines ; body soaleless, naked, or mailed. 



Gastbrostbid^ 



FAMILY XXVI. GASTEROSTEiD^. 

 THE STICKLEBACKS. 



Body elongate, somewhat compressed, tapering behind to a slender caudal peduncle; 

 head rather long, the anterior part not produced into a tube ; mouth moderate, the cleft 

 oblique, the lower jaw prominent ; teeth sharp, even, in a narrow band in each jaw ; 

 no teeth on vomer or palatines ; premaxillaries protractile ; prenrbital rather broad ; sub- 

 orbital plate large, often covering the anterior part of the cheeks, connected with the 

 preopercles ; opercles unarmed ; branchiostegals three ; gill-membranes broadly united, 

 free, or joined to the isthmus ; gill-rakers moderate ; no true scales, the skin naked or 

 with bony plates; dorsal with its spines disconnected, two or more in number; anal 

 similar to soft dorsal, armed with a single spine ; ventral fins snbabdominal, each con- 

 sisting of a single sharp spine and a rudimentary soft ray ; middle or sides of belly 

 shielded by the innominate bones; pectorals short, placed at a considerable distance 

 from the gill openings from which they are separated by a quadrate, naked area covered 

 with shining skin ; caudal fin narrow, usually lunate ; air-bladder simple ; a few pyloric 

 coBca ; genera 5, the two mentioned are, however, scarcely worthy of separation from 

 Gasterosteua. About twenty species are known, most of them of very wide distribution 

 in the rivers and bays of northern regions. They are all of small size, and are exceed- 

 ingly active, pugnacious, and destructive. 



"It is scarcely to be conceived what damage these little fishes do, and how greatly 

 detrimental they are to the increase of all, the other fishes among which they live, for it 

 is with the utmost industry, sagacity, and greediness that they seek out and destroy aU 

 the young fry that come their way." 



The Sticklebacks buUd elaborate nests in the spawning season. These the male fish 

 defends with much spirit. 



Analysis of Genera of GASiEROSTBiDiE. 



a. Innominate bones joined together, forming a triangular or lanceolate bony piece 

 on the middle line of the abdomen behind the ventral fins; gill- membranes 

 posteriorly free from the isthmus. 

 6. Dorsal spines 4 to 6, in the same line when erected ; no caudal keel, bucalia. 87 

 66. Dorsal spines 8 to 10, not in a right line when erected, but projecting altern- 

 ately to the right and left ; caudal keel present. . . . PYG08TBUS. 88. 



Genus 87. EUCALIA.. Jordan. 



Gasterosteus sp., Kirtlasd, Storbr, and others. 



Eucalia, Jordan, Man. Vert., Ed. 1st, 1876, 248 ; Proc. Acad. Nat. So. Phila., 187?, 65. 



Type, Gasterosteus inconstans, Eirtland. 

 Etymology, eu, well; Jcalia, nest. 



