142 THE NAUTILUS. 



in this particular animal. The posterior edge of the collar was 

 higher than the anterior one, and when both " rhinophores " 

 were retracted this posterior border of the collar was folded 

 over the anterior edge in such a way as to lead to the appearance 

 of two minute openings into the single pocket. 

 Agar's Island, Bermuda. 



REFERENCES 



AREY, L. B. 1917. The sensory potentialities of the nudibranch " rhino- 

 phore." (Proc. Amer. Soc. Zool., 14th Ann. Meet.) Anat. Record. 

 Vol. 11, No. 6, p. 514-516. 



CROZIER, W. J. 1917. The nature of the conical bodies on the mantle of 

 certain nudibranchs. 

 NAUTILUS, Vol. 30, p. 103-106. 



SMALLWOOD, W. M. 1910. Notes on the hydroids and nudibranchs of 

 Bermuda. 

 Proc. Zool. Soc. London, 1910, Part I, p. 137-145. 



DESCRIPTION OF FIGURES, Plate VI. 

 FIG. 1. Branching gills. 

 FIG. 2. Ridges about the branchial collar; a, anterior; 6, posterior; c, 



branchial collar (gills not shown); d, triangular depressions. 

 FIG. 3. Lobed condition of the buccal veil. 

 FIG. 4. A bifurcate rhinophore; c, collar of rhinophore. 

 FIG. 5. Fused rhinophoral pockets; a, rhinophores extended; 6, retracted. 



A METHOD OF PRESERVING LARGE NUDIBRANCHS. 



W. J. CROZIER. 



Contributions from the Bermuda Biological Station for Research, No. 65. 



Those who have had occasion to study collections of nudi- 

 branchs, especially when they include specimens of the larger 

 tropical species, have doubtless often wished that the organisms 

 submitted for their examination had been so preserved as to 

 exhibit in more natural fashion the appearance of these crea- 

 tures when alive. After various attempts to secure good prepa- 

 rations, I find that the simple procedure herein outlined gives 

 tolerably fair results. The method has been tried almost ex- 

 clusively upon Chromodoris zebra, but it seems likely that 

 other large forms will yield equally good preservations when 

 treated in the same way. 



A saturated solution of cocaine hydrochloride is made up in 

 sea water, and 2-3 cc. of this solution is then injected into the 



