746 Bulletin 47, United States National Museum. 



Ga&terosteus nebulosus,* AGASSIZ, Lake Superior, 310, pi. 4, fig. 4, 1850, Lake Superior. 

 Gasterosteus dekayi, AGASSIZ, Lake Superior, 311, 1850, New York. 

 Gasterostem lotharingus, BLANCHARD, Poiss. France, 244, 186G, Gordon, Lorraine. 

 Gasterosteus breviceps, BLANCHARD, Poiss. France, 245, 1866, Caen, France. 

 Gaslerostea blanchardi,^ SAUVAGE, Kevision des pinoches, 32, 1874, New York. 



Represented in Greenland and the far north by 



1097a. PYGOSTEUS PUNGITIUS BRACHYPODA (Bean). 



D. X-I, 10 ; A. 1, 10. Similar to P. pungitius, but the ventral spines very 

 short, their length a little less than that of head. Mountain streams and 

 lakes, about Baffins Bay ; * locally abundant ; not seen by us. (/3pa;t^r, 

 short; TTOV^, foot.) 



Gaslerosleus pungitius brachypoda, BEAN, Bull. IT. S. Nat. Mus., xv, 129, 1879, Oosooadlin Moun- 

 tain, Cumberland Gulf, Greenland. (Type, Nos. 21738, 21766, etc. Coll. Kumlein.) 

 JORDAN & GILBERT, Synopsis, 394, 1883; EIGENMANN, I. c., 236. 



338. GASTEROSTEUS (Artedi) Linnaeus. 

 (STICKLEBACKS.) 



Gasterosteus (ARTEDI) LINNAEUS, Syst. Nat., x, 1758, 489, (aculeatus). 

 Gasteracanthus, PALLAS, Mem. Ac. St. Petersb., in, 325, 1811, (catapliractus). 

 Leiurus, SWAINSON, Nat. Hist. Class'n Fishes, n, 242, 1839, (gymmirus). 



Sticklebacks with the innominate bones coalescent on the median line 

 of the belly, behind and between the ventral fins, forming a triangular or 

 lanceolate plate. Gill membranes united to the isthmus. Tail slender, 

 and usually keeled. Skin variously covered with bony plates. Dorsal 

 spines 3 in number, strong, with nondivergent bases. Species numerous. 

 Fresh waters and shores of all northern regions ; the species highly varia- 

 ble, those found in the sea usually with the body completely mailed, the 

 fresh and brackish water forms variously mailed or even altogether naked. 

 It is probable that the reduction in armature is in some degree connected 

 with life in fresh waters. It is also probable that the partially naked 

 fresh-water forms of Europe and northeastern and northwestern America 

 have been in each case derived from the mailed marine forms of the same 

 region. In Europe, the mailed and partly naked forms are scarcely sep- 

 arable as varieties. In western America, the division is better established, 

 and the naked and partially naked forms seem definable as distinct spe- 

 cies, each with large variation within its range, (yaar^p, belly ; OGTEOV, 

 bone.) 



a. Species of the eastern Atlantic, robust, with short dorsal spines, each one when depressed 

 not reaching the next. ACULEATVS, 1098. 



aa. Specie of the western Atlantic, more slender, with longer spines. BISPINOSUS, 1099. 



aaa. Species of the eastern Pacific, robust, the marine forms with long spines. 



b. Species marine, the body wholly mailed, the plates well developed throughout. 



CATAPHRACTUS, 1100. 



W>. Species of fresh or brackish waters, not wholly mailed, or with the posterior plates 

 very small. WILLIAMSONI, 1101. 



* The common Alaskan form referred by Dr. Bean to this subspecies, seems to be nearer the 

 typical pungitiiis, having the ventral spines nearly half length of head. 



