III. 



COTTOIDS OF NORTH AMERICA. 



75 



EXPLANATION OF THE PLATES. 



PLATE I, and Pigs. 1 10 of PLATE II, need no further explanation beyond what is written at the bottom 

 of those plates. 



PLATE II, Fig. 11, represents the skeleton of Triylopsis 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 Coitus viscosus on Plate III, of which a table is given immediately 

 below. 



PLATE III, Figs. 1 3, represent the muscular masses of G. viscosus, and the peculiar bondings 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 b , the hyoidean apparatus; in Fig. 5 C , the branchial apparatus; in Fig. 5 d , 

 the ventral fins; and in Fig. 5 e , some of the pieces constituting the trunk. 



8'. Supramastoids. 

 13. Vomer. 



19. Turbinal. 



20. Palatine. 



21. Maxillary. 



22. Premaxillary. 



23. Entopterygoid. 



24. Pterygoid. 



25. Epitympanic. 

 20. Mesotympanic. 



27. Pretympanic. 



28. Hypotympanic. 



29. Articular. 



30. Angular. 



31. Splenial. 



32. Dentary. 



34. Preopercular. 



35. Opcrcular. 



36. Subopercular. 



37. Interopercular. 



38. Stylohyal. 



39. Epihyal. 



40. Ceratohyal. 



41. Basihyal. 



42. Glossohyal. 



43. Urohyal. 



44. Branchiostegals. 



45. Basibranchials. 



46. Hypobranchials. 



47. Ceratobranchials. 



48. Epibranchials. 



49. Pharyngobranchial. 



49'. Inferior Pharyngobrancliial. 



50. Suprascapular. 



51. Scapular. 



52. Coracoid. 



54. Ulna. 



55. Radius. 



56. Carpals. 



57. Metacarpo-plialangeals. 



58. Epicoracoid. 

 63. Pubic. 



70. Metatarso-phalangeals. 



71. Supraorbital. 



72. Supratympanic. 



73. Lachrymal. 



73". I 



Yg b f Supralachrymals. 



73'. 



