98 TELKOSTEI : PERCESOCES. — XIX. 



notlcrinal jtlati-s, tlu' Iwiie;* and sjiincs all feeble; tail keeled. H('a<l 

 8^; depth 4. D. IV-I, 10. A. I, 10. L. 2^. N. Y. to Kansas 

 and tirecnland, abundant N. W. in small brooks; S. to Greensburg, 

 Ind. (Shannon.) Var. cayuga Jordan (W. N. Y.) has V. spines 

 longer, longer tlian innnoniiiiate bones, and other trilling differences. 



110. GASTEROSTEUS (Artedi) Linnanis. 

 (^yaiTTTJp, l)eily; oartov, Injne.) 



a. Sides partly covered with bony plates, the tail naked. 

 b. Lateral plates 2 to 7. 



c. Ventral spine without cusp at base; lateral plates 2 or 3. 



240. G. •wheatlaJidi rutnam. No mucous pores; tail com- 

 pressed. Hlackish. 1). II, I, 10 to 12. A. I, H. Cape Cod, N. 

 scarce. (To Dr. Richard II. Wheatland, of Salem, Mass.) 



cc. Ventral spine with a strong cusp at base behind; lateral plates 

 about 7. 



241. G. gymnuruB Cuvier. Tail keeled. Grayish, dotted. 

 1). II, I, 12. A. I, 8. L. 2^. Newfoundland to Greenland, etc. 

 {G. dimidiatus Reinhardt.) (Eu.) (yv/ii/dr, naked; oupa, tail.) 



bb. Lateral plates 15: tail keeled. 



242. G. atkinsii Bean. Slender; V. long. Head .TJ; depths. 

 D. II, I, 11. A. I, 8. L. 1^. Maine. (To Charles G. Atkins, 

 Fish Commissioner of Maine.) 



aa. Sides entirely covered with (28 to 33), bony plates; tail keeled; V. spine 

 with cusp at base. 



243. G. aculeatus L. Common STiCKLF.n.^CK. Olivaceous, 

 sides silvery ; back dotted ; opcrcles striate ; rugose plates at base 

 of spines; spines serrate. Head 3^; depth 4^. I). II -I, 13. A. 

 I, 9. L. 4. N. Y. to Greenland and P^urope, abundant, variable, 

 (iiu.) Perhaps all the preceding are forms or varieties of tliis. 

 (Lat., bearing prickles.) 



111. APELTES DcKay. (a, privative ; ttcXtt;, shield. 



244. A. quadracus (Mitchill). Olive, mottled; males nearly 

 black, the V. red in spring ; body plump, with long slender tail ; 

 skin naked. Head 4; depth 4. I). Ill, I, 11. A. I, 8. L. 2. 

 N. J. to Labrador ; abundant along coast. (Lat., four-spined.) 



Order XIX. PEKCESOCES. 



This group comprises Physoclysti. whidi have the general cliar- 

 acters of the great group of Acanthoptcri, but in which the ventral 

 fins are abdominal, the pelvic bone not being attached to the 

 hhoultler-girdle. Scales cycloid, opercles unarmed. The si)iiH)US 

 tlurbal is short and sometimes (Ujj/iiucij//ialida) wanting. (Lat., 



