MUSEUM OF COMPARATIVE ZOOLOGY. 203 



Onchidium Floridanum, Dall. 



See Plate VI. Figs. B, C, for a drawing of an original specimen, enlarged 

 three times. 



To Mr. Hemphill is due the credit of adding this genus to the fauna of Eastern 

 North America. The specimens arrived as this paper is going through the press, 

 and a detailed description must be deferred. The following notes, however, will 

 indicate its external characters : — 



When living, the creature is of a uniform slaty blue, the under parts bluish 

 white, with a greenish tinge to the veil. The surface appears beautifully smooth 

 and velvety without dorsal tubercles ; just within the slaty margin of the mantle 

 is a single row of about (in all) one hundred whitish elongated tubercles. When 

 crawling, it is of an oval shape, about an inch long, and two tentacles extend for- 

 ward beyond the mantle margin, resembling the oculiferous ones of Vaginulus 

 Floridanus. In spirits the surface is still smooth, but numerous circular hardly 

 elevated domelets cover the back, each appearing to contain one of the dorsal eyes 

 described by Semper. The tentacles are entirely retracted ; a narrow veil, with 

 lightly escalloped edge, precedes the head ; the muzzle is not prominent, is in- 

 dented in the middle, and puckered at the edges. The foot is about one third 

 wider than the mantle at each side of it. There is no jaw. The penis resembles 

 that of Siphonaria in form and position. The animal exudes very little mucus. It 

 was found on rocks between tides associated with Chiton piceus. Fifteen speci- 

 mens were found at Knight's Key by Hemphill. 



Onchidium indolens of Couthouy (Rio) and 0. armadillo of Morch differ from the 

 above in coloring. The latter, described from St. Thomas, has a very different 

 dorsal surface. No others are known from East America. It would seem as if 

 the small Northern species, possessing a jaw like 0. boreale, Dall, and 0. Celticum, 

 Cuvier, might appropriately be separated from the agnathous tropical forms as a 

 subgenus, for which the name of Onchidella might be revived in a restricted sense. 



The above description is by Dall (Proc. U. S. Nat. Mus., 1885, p. 288). 

 Specimens received by him have the lingual dentition of the genus. (See my 

 Plate III. Fig. 10, where a central tooth and adjacent lateral are given.) There 

 are numerous rows of over 97-1-97 teeth. 



The following are to be added to the species treated in the Second Sup- 

 plement. 



PACIFIC PROVINCE SPECIES. 



Microphysa Stearnsi, Bland. 

 Lansingi, Bland. 



It must be borne in mind that the other species of Microphysa examined by 

 me have quadrate marginal teeth, while Stearnsi and Lansingi have the acule- 

 ate marginal teeth of the Vitrinince. Thus they can hardly be classed in 

 Microphysa. The name Pristina has been suggested by Ancey (Conchologists' 



