COTTIDA. — LXXIII. 149 
6b. Preopercular spines small, mostly concealed by the skin; skin smooth 
or prickly in or behind the axil only. (Potamocottus Gill.) 
406. C. richardsoni Agassiz. MiILLter’s Tuums. Bros. 
Murrie-saw. Body rather stout, the head very broad; pre- 
opercle with a short, sharp, straightish spine, turned upward and 
backward, with 2 smaller spines below it. Olivaceous, much barred 
and speckled. Head 34; depth 4 to6. D. VI to VIII-16. A. 
12. V. 1,4. L. 3 to 7. Lake Superior to Ark., Ga., Md., and 
Canada very abundant in springs, caves, cold lakes, and rocky 
brooks. Very variable. The numerous varieties or nominal spe- 
cies are hardly worthy of recognition by name. (To John Rich- 
ardson, author of the “ Fauna Boreali-Americana.”) 
aa. Palatine teeth, none; V.I, 8; skin mostly smooth. (Cottus.1) 
ce, Anal rays 18 or 14. 
d. Preopercular spine large, hooked upward. 
407. C. pollicaris (Jordan & Gilbert). Light olive, blotched 
and spotted with black, but not speckled; upper fins spotted. Eye 
54 in head. Head 32; depth 43. D. VII-19. A. 13. L. 5. 
Lake Michigan. (Lat., thumb-like.) 
408. C. spilotus (Cope). Olive, everywhere closely speckled 
with darker except on belly; sides barred with blackish; fins 
barred and spotted. Eye 44 in head. Head 34; depth 5. D. 
VIII-17. A. 13. L. 3 Grand Rapids, Mich. (omAords, 
spotted.) 
dd, Preopercular spine short, acute, turned obliquely upward. 
409. C. viscosus Haldeman. Stout, with many mucous pores; 
fins low. Olivaceous, body and fins mottled with dark ; 1st D. with 
red edge. Head 3}; depth 43. D. VI-18. A.14. Penn. to Md. 
ec. Anal rays 11 or 12.” 
ce. Preopercular spine short, scarcely hooked. 
J. Preopercular spine bent upward and backward. 
410. C. gracilis Heckel. Body rather slender; fins large. Oliva- 
ceous, mottled, 1st D. edged with red. Head 34; depth 44 to 5}. 
D. VIII-16. A.12. L.4. N. Eng. and N.Y. (Var. gobioides 
Grd., with robust body, and var. boleoides Grd., with slender body 
and long fins, have been described.) (Lat., slender.) 
Jf. Preopercular spine directed backward and scarcely upward. 
411. C. hoyi Putnam. Slender; 9 prickly above; jaws nar- 
rower and mouth smaller than in C. gracilis ; another spine below 
it turned downward, and one or two others still lower. Olivaceous, 
speckled and barred. D. VI-15. A. 11. L. 2. L. Michigan. 
(To Dr. Philo R. Hoy.) 
ee. Preopercular spine distinctly hooked. 
1 The species of this group have never been critically studied ; some of them are 
doubtful, and most of them may prove to be mere varieties of Cottus gracilis. 
