Iii. 
COTTOIDS OF NORTH AMERICA. 75 
EXPLANATION OF THE PLATES. 
PuateE I, and Figs. 1—10 of Puare I, need no further explanation beyond what is written at the bottom 
of those plates. 
Prare II, Fig. 11, represents the skeleton of Zriglopsis Thompsonii. At pages 21, 22, we have alluded 
to some deficiencies in the general figure. The numbers appended to the bones of the face, as 
well as the initials, are those adopted by Prof. Owen. The numbers 1—12, which accompany 
the vertebrae, do not indicate their number in the series; we have allowed these numbers to be 
affixed in order to be more precise in alluding to any one of them. All these pieces have been 
homologized with those of Cottus viscosus on Plate LI, of which a table is given immediately 
below. 
Prate IL, Figs. 1—3, represent the muscular masses of C. viscosus, and the peculiar bendings of the 
myocomma, seen in profile in Fig. 1, from the belly in Fig. 2, and from above in Fig. 3.— 
Fig. 4 represents the muscles which move the branchiostegal apparatus.—Fig. 5 is a general 
view of the skeleton of C. viscosus—In Fig. 5°, the bones of the face and scapular arch are 
exhibited; in Fig. 5°, the hyoidean apparatus; in Fig. 5°, the branchial apparatus; in Fig. 54, 
the ventral fins; and in Fig. 5°, some of the pieces constituting the trunk. 
8’. Supramastoids. 43. Urohyal. 
15. Vomer. 44. Branchiostegals. 
19. Turbinal. 45. Basibranchials. 
20. Palatine. 46. Hypobranchials. 
21. Maxillary. 47. Ceratobranchials. 
22. Premaxillary. 48. Epibranchials. 
25. Entopterygoid. 49. Pharyngobranchial. 
24. Pterygoid. 49’. Inferior Pharyngobranchial. 
25. Hpitympanic. 50. Suprascapular. 
26. Mesotympanic. 51. Scapular. 
27. Pretympanic. 52. Coracoid. 
28. Hypotympanic. 54. Ulna. 
29. Articular. 55. Radius. 
30. Angular. 56. Carpals. 
31. Splenial. 57. Metacarpo-phalangeals. 
32. Dentary. 58. Epicoracoid. 
34. Preopercular. 63. Pubic. 
35. Opercular. 70. Metatarso-phalangeals. 
36. Subopercular. 71. Supraorbital. 
37. Interopercular. 72. Supratympanic. 
38. Stylohyal. 73. Lachrymal. 
39. Hpihyal. 159) 
40. Ceratohyal. 730, \ Supralachrymals. 
41. Basihyal. 73’. Suborbitals. 
42. Glossohyal. 
