COLUMBELLA. Panama Shells. 95 



whorls smooth or with one or two revolving strife; middle 

 whorls with twelve to fifteen ribs, with the interstices spirally 

 striate ; with the ribs and striae obsolete on the back of the last 

 whorl ; more strongly striated anteriorly : apex acute : spire 

 very slender: whorls eight, scarcely convex, with the suture 

 lightly impressed: aperture long and narrow: labrum varici- 

 form, very thick, sinuate posteriorly, crenulated within : colu- 

 mellar lip nearly smooth. 



Mean divergence about 35 ; length .3 inch ; breadth .11 

 inch ; length of spire .17 inch. 



Station. We found this species about sticks and stones in a 

 grove of trees, a little above half tide level. 



Habitat. Panama ; C. B. 'A. ! 



58 specimens were obtained about two rniles west of the city. 



97. Columbella nigricaiis. 



Synonymy. 



Columbella nigricans Sowb. in Proc. Zool. Soc. Lond. p. 52. Mar. 1844. 



Duel, in Chenu, 111. Conch, pi. 21. f. 7, 8. 



Sowb. Thes. Conch, p. 143, No. 95. pi. 40. 



f. 172. 



Station. Our specimens were found under stones, between 

 half tide and low water mark. 



Habitat. Gallapago Is. ; Cuming ! Sowerby. 

 Gallapago Is. ; Jay. 

 Taboga ; E. Jewett ! Gould MSS. 

 Panama and Taboga ; C. B. A. ! 



We obtained on the reef about 120 specimens of large size, 

 most of which are colored as described by Mr. Sowerby. 

 About 500 specimens of small size were collected, among which 

 there is a great diversity of coloring. Many have a white spiral 

 band. All shades of brown occur. Some of the small indi- 

 viduals are likely to be confounded with C. parva Sowb. ; but 



