248 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Seb. 



Let us now pass to column 3. Pilsbry, who is a careful ob- 

 server, states that beyond the bristles the girdle is imde. This 

 statement and the unusual size of his type specimen do not fit in 

 well with the remainder of the table, though the weight of all 

 the rest of the evidence would indicate that Mopalia heathii 

 Pilsbry must fall as a synonym of T. ilectens. Can it be barely 

 possible that there are tzvo species involved in the original de- 

 scription of M. heathii? This, with other correlative points, 

 will receive attention in a later communication. 



From evidence before me, my present inclination is to give 

 both Trachydermon Carpenter, as redefined (type: T. flectens 

 Carpenter), and Dendrochiton Berry, 1911 (type: Mopalia 

 (D.) thamnopora Berry) full generic rank, referring both, 

 though only tentatively, to the family Mopaliidse. 



Literature Cited 

 Berry, S. S. 



:11. A new Californian chiton. Proceedings Academy of 

 Natural Sciences of Philadelphia, 1911. pp. 487-492, text figs. 

 1-7, pi. 40, October, 1911. 



Iredale, Tom. 



:14. Some more notes on Polyplacophora. Part I. Pro- 

 ceedings Malacological Society, London, v. 11, pp. 123-131, 

 June, 1914. 



Pilsbry, H. A. 



'92. Monograph of the Polyplacophora. (Lepidopleuridse, 

 Ischnochitonidae, Chitonidse, Mopaliidae). Manual of Con- 

 chology, V. 14, pp. i-xxxiv, 1-350, pi. 1-68, Philadelphia, 1892. 



'93. Monograph of the Polyplacophora. (Acanthochitidse, 

 Cryptoplacidae, and Appendix.) Manual of Conchology, v. 

 15, pp. 1-132, pis. 1-17, Philadelphia, 1893. 



'98. Chitons collected by Dr. Harold Heath at Pacific 

 Grove, near Monterey, California. Proceedings Academy of 

 Natural Sciences of Philadelphia, 1898, pp. 287-291. 



