CHITONS TAKEN BY THE UNITED STATES FISHERIES 

 STEAMER "ALBATROSS" IN THE NORTHWEST PACIFIC 

 IN 1906. 



By S. Stillman Berry, 



Scripps Institution fur Biological Research, La Jolla, California. 



A small series of chitons taken in the course of the Northwest 

 Pacific Expedition of the United States Fisheries Steamer Albatross 

 during the summer of 1906 was kindly transferred to the writer by 

 Dr. Harold Heath, of Stanford University, for study and report, and 

 forms the subject matter of the present paper. Though rich neither 

 in species nor in individuals, the fact that our knowledge of the chiton 

 fauna of this region is slight and the fortunate circumstance that the 

 specimens were kept in alcohol render the material noteworthy. 

 The collection comprises in aUsome 45 specimens. These are referable 

 to 11 species, of which the 4 named below are described as new: 



Leptochiton diomedeae, new species. 



Ischnocliiton (Lepidozona) amahilis, new species. 



IschnocTiiton {Lejndozona) interfossa, new species. 



Ischnocliiton (Lepidozona) pilshryanus, new species. 



Family LEPIDOPLEURIDAE. 



Genus LEPTOCHITON Gray 1847. 



LEPTOCHITON DIOMEDEAE, new species. 



Plate 1, figs. 1-3; plate 2. 



Description. — Shell rather small, elliptical, the shell and girdle 

 together approximately twice as long as broad. Insertion plates 

 lacking. Valves moderately elevated, sharply arcuate. Anterior 

 valve with a concave anterior slope due to the apical region rising 

 more abruptly than the slightly flaring marginal region; posterior 

 margin broadly /\ -shaped in outline when the valve lies in its normal 

 position. Median valves with small but sharp and rather prominent 

 beaks, their anterior margins only slightly arcuate except the second 



Proceedings U. S. National Museum, Vol. 54— No. 2223. 

 3343— 19— Proc.N.M.vol.54 2 1 



