10 THi: NALTlLLs. 



lines rather coarse and irregular, the entire surface covered with 

 low, coarse, rather distant radial striae extending to the edges. 



Length 3.5, width 2.o, alt. 1 nnu. 



Types, (No. 43454 Cull. Walker), from Butting Kam Shoals, 

 Coosa Co., Ala., collected by H. H. Smith. Cotypes in the 

 collections of T. H. Aldrich, George H. Clapj) and John H. 

 Henderson. 



All of the specimens were found on living Pleuroceridie. 



This beautiful little species, which groups with rhodicme in 

 its depressed shape and spine-like apex as well as in its radular 

 characteristics, differs from it in its small size, more regularly 

 oval shape and the greater development of radial strije over the 

 surface. 



It is named in remembrance of the late Rev. Prof. H. M. 

 Gwatkin of Caml^ridge, England, to whom I am indebted for 

 practically all of the radula preparations used in this paper and 

 who was the first to observe and point out the remarkable char- 

 acter of the radula in the different species of the genus. 



I am indebted to Dr. Pilsbry for the slide representing the 

 radula of Lanx ijatelloides. All of the other radula? figured 

 were prepared by Prof. Gwatkin, and all of the figures were 

 drawn by Mrs. Lydia M. H. Green formerly connected with the 

 U. S. National Museum. 



A NEW SPECIES OF ASTAETE FKOM ALASKA. 



BY WILLIAM HEALEY DALL. 



In 1865 Dr. Philip Carpenter described from a single speci- 

 men a species of Astarte from Puget Sound, to which he gave 

 the specific name of compada. This type remains in the collec- 

 tion of the National Museum as number 4509. 



This species has remained extremely rare, only three or four 

 others, some eroded and doubtful, have come to hand during 

 the half-century which has passed. This is probably due to 

 the fact that the right locality had not been dredged, for the 



