THE NAUTILUS. 107 



California and the Rocky Mountain States, and may be regarded 

 as a supplement to Carpenter's collection of papers on West 

 American Mollusks. It is not arranged systematically but an 



index enables one to find any species. 



H. A. P. 



NOTES 



A STAIN FOR RADULAE. In many of the small mollusks it is 

 difficult to make out the exact shape of the teeth on the radula 

 because of their transparency. Moreover, a radula mounted in 

 balsam becomes almost invisible in a short time. I have found 

 that the radula may be readily stained without injuring the teeth 

 of even the most delicate forms and without loosening them 

 from the lingual ribbon. 



For the marine forms, place the radula in a saturate aqueous 

 solution of potassium bichromate for from five to fifteen min- 

 utes. However, the radula may remain in the stain without 

 injury for an indefinite period. One radula left in this solution 

 for three months was not harmed in the least. After staining, 

 wash well in water and mount in balsam. 



Land and freshwater forms cannot be handled in this way. 

 For these a five per cent, solution of chromic acid works admir- 

 ably. Place the radula on a slide, cover with four or five drops 

 of the acid, and heat until the acid precipitates at the edge of 

 the drop. If heated too long, the teeth may become detached 

 from the lingual ribbon. Wash in water and mount in balsam. 



These stains seem permanent in balsam, specimens so pre- 

 pared having kept for eight months without fading, while spe- 

 cimens in glycerine jelly fade in a month or two. Though I 

 presume other stains for radulae are known, these appear to be 

 practical both in the simplicity of the process and the perma- 

 nency of the stain. SHIELDS WARREN. 



A NEW VARIETY OF CYPRJEA. Cyprsea undata buttoni, n. v. 

 White, ornamented with three zigzag zones of chestnut, show- 

 ing fine hair lines of chestnut between the zones ; sides and base 

 white ; anterior extremity edged dark chestnut. Length, .50 to 

 .75 inch. 



