6 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



4. New Chitons Collected by Dr. Harold Heath in 

 Monterey Bay, California 



From time to time considerable interesting material in the 

 way of chitons preserved in alcohol, principally from collec- 

 tions made by himself in the neighborhood of Pacific Grove, 

 California, has been placed in my hands for study by Dr. 

 Harold Heath of Stanford University. On the whole the 

 list of species represented in his collections in this region is 

 much the same as that given by Pilsbry ('98) some twenty 

 years ago from material taken by the same collector, but 

 three of the forms now before me, including a member of 

 one genus totally new to our fauna, appear to have been 

 previously undescribed. Preliminary descriptions of these are 

 accordingly given below. 



Genus Leptochiton Gray 1847^ 

 Subgenus Xiphiozona Berry 1919 

 Leptochiton (Xiphiozona) heathi Berry 1919 

 PI. 1, figs. 1-2; pi. 2 



Diagnosis: Shell small, oval, well arched, the jugum ob- 

 scurely angled ; side slopes strongly convex. 



Anterior valve with numerous (100-120), closely placed, 

 radial series of minute, low, round, flattened pustules, usually 

 distinct from one another and not overlapping. Median 

 valves not beaked, their sculpture similar to that of the 

 anterior valve; lateral areas not raised, poorly defined, their 



^ I am not entirely certain as to the proper generic name to be used for most 

 of our West American Lepidopleurids. Iredale (:14, p. 127-128) has lately reminded 

 us that by reason of Gray's own designation Chiton cinereus must be regarded as 

 the orthotype of his genus Leptochiton. This is a Linnean species belonging, as 

 shown by Hanley, to quite a different group than the shells which have been 

 referred to Leptochiton by most or all subsequent authors. If this were all. we 

 would at once be barred from using Leptochiton in the present connection at all, 

 and this is evidently the opinion of Iredale. But the trouble comes in when we 

 remember, as has been pointsd out by Pilsbry ('92, p. 14), that L. cinereus, as in- 

 terpreted by Gray, appears not to be the Linnean form, but really the Chiton 

 asellus of Spengler, which is a Lepidopleurid. Whether, under a strict construction 

 of the International Code, we must call Chiton cinereus Linnaeus the type of Lepto- 

 chiton Cray, or whether cinereus Montagu, Gray, et al. (non Linna:us) can be re- 

 tained in this office, I cannot decide without access to more of the relevant litera- 

 ture than is now available to me. Nor, if Leptochiton be unavailable, can I sug- 

 gest just what name had best be used in place of it. One has, of course, the 

 option to fall back, for the time being, on the old blanket name Lepidopleiirus 

 Risso, that long-enduring receptacle for every chiton without recognizably developed 

 insertion plates one is otherwise uncertain what to do with. But as the Californian 

 species seem none of them to be properly congeneric with L. cajetanus (Poll), the 

 Mediterraneo-Atlantic species which is the type of Risso's genus, I prefer for the 

 present to retain Leptochiton with the explanation above given. 



