CHITONS. 41 



are most lik' 1 y to be met with by those who 

 read this little book. 



Ischnochiton Magdalensis, lids.. Fig. 3, PL 

 XT, Lean Chiton, isfvery common, and may be 

 found abundantly by turning over stones at low 

 tide. It is long and lean, as its name implies. 

 The valves are light colored, spotted without, and 

 wh'te within. The grayish mantle is set with 

 minute scales. It varies in length from one to 

 three incites. 



Mopalia muscosa, Gld., Fig. 4, PI. XI, Mossy 

 Chiton, is common all along the* west coast of 

 the United States. It is more compact than the 

 last species and the plates are more highly sculp- 

 tured. The mantle is set with strong hairs or 

 points, like a chestnut bur. Outside, its color 

 is dark, but within the valves are of a light green. 

 Length, two inches. 



The large chiton shown in Fig. 5, PI. XI, was 

 named Katherina Doglasice by Dr. Gray of the 

 British Museum, in honor of Lady Khtherine 

 Douglass, who first sent a specimen to that in- 

 stitution. It is now called Katherina tunicata, 

 Sby., an older specific name having been discov- 

 ered and applied. If we were to put her lady- 

 ship's rather lengthy name into familiar Erglish, 

 we could do no better, perhaps, than to call this 

 famous mollusk, the Black Katy. Its form is 

 well shown in the figure, long and oval. The 

 mantle is black .and heavy,*nearly covering the 

 white shell-plates ; the foot is reddish ; common 

 length, two to three inches. If may bp found 

 on the rocks at the entrance to the Golden Gate, 

 when the tide is low, but its peculiar home is 



