58 Panama Shells' purpuridjj. 



Acapuloo ; Humboldt and Bonpland ! Valenciennes. 

 West coast of Mexico ; Say in Catal. Mua. 

 Mexico, California, Panama; Duclos. 

 Panama ; Cuming ! Reeve j also Moroh. 

 Panama ; Jay. 

 Panama; C. B, A. ! 



We collected 4,500 specimens, 



42. Planaxis planicostata. 



Synonymy. 



Planaxis planicostata Sowb. in Tank. Catal. No. 1418. App. p. 13. 1825. 

 Buccinum planaona Wood Ind. Test. Supp. pi. 4. f. 15. 1828. 



Planaxis canaliculata'Du\a\. \u'&&y.Zoo\. • Apr. 1840. 



Trosch. ia Wiegm. Archiv. p. 271. 1840. 



planicostata Reeve Elem. Concb. pi. B. f. 17. 1846. 



The epidermis of this shell is exceedingly thick and tena- 

 cious, and of a dingy olive green. Beneath the epidermis the 

 shell is black, but near the apex and in faded specimens the 

 color is brown. All the specimens at Panama and in one spot 

 at Taboga belong to a large variety, and are often more than 

 an inch long. The others at Taboga were mostly from .6 inch 

 to .7 inch lonp;. 



-o* 



Station. — Under stones between high water and half tide 

 level. 



Habitat. — Gallapago Is. ; Sowerby : also Duval : also Jay. 

 Panama ; E. Jewett ! Gould Mss. 

 Taboga and Panama ; C. B. A. ! 



At Taboga in incredible numbers : less common on the 

 reef at Panama. We collected about 1200 specimens. 



