The Nautilus. 



Vol. XIX. OCTOBER, 1905. No. 6. 



DESCRIPTION OF A NEW SPECIES OF GONIOBASIS, FROM BRITISH 



COLUMBIA. 



BT J. F. WHITEAVES. 



Goniobasis Columbiensis sp. nov. Plate 2, figs. 11, 12. 



Shell small (for the genus), apparently not exceeding fifteen mil- 

 limetres in length, elongate conical and about twice as long as wide, 

 spire rather short, a little shorter than the outer whorl, as viewed 

 dorsally. Whorls actually five or six, but probably seven when per- 

 fect, the apex being always eroded ; those of the spire obliquely 

 compressed, the later ones thereof encircled with one to three very 

 small spiral ridges or keels in some immature specimens, but smooth 

 in full-grown ones. Outer whorl moderately convex, faintly and 

 spirally angulate at the midlength in the immature stage but rounded 

 in the adult, its lower or anterior portion always narrowing rather 

 abruptly ; sutural line impressed. Aperture subovate, longer than 

 wide, acutely pointed posteriorly, produced and somewhat effuse but 

 narrowly rounded in front, almost ecpual to the spire in length ; outer 

 lip thin and simple. 



Surface of full-grown specimens almost smooth, and marked only 

 with very numerous and closely disposed striae that are parallel with 

 the outer lip and so minute as not to be visible without the aid of a 

 lens ; also with one or two distant lines of growth that mark the 

 position of previous lips. 



Epidermis uniformly brownish or greenish-brown, without darker 

 bands ; aperture and inner surface of the last volution a lustrous 



