84 



THE NAUTILUS. 



lacking entirely, there being one broad dorsal band of darker 

 reddish brown, bounded on each side by a narrow row of more 

 or less connected black spots. 



In the eighteen specimens of this lot examined, all possessed 

 a rudimentary shell. In many cases, in spite of the greatest 

 care in making the incision in the mantle, the shell had become 

 dislodged from its normal position. In eight specimens it re- 

 mained attached to the animal when found. In all of these 

 specimens it was adherent to the outer surface of the inner 

 membrane or peritoneum, and not connected in any way to the 

 inner surface of the mantle. It also, in the specimens in which 

 it remained fastened, was always in the posterior quarter of the 

 iuiimal, and over some portion of the liver. In two of the 

 eight specimens it occurred on the left side, in two directly on 

 top, and in four on the right side of the liver. The diagram 

 (fig. 1) was made from a specimen (M. C. Z. 48211 II ) meas- 

 uring 40 mm. in length in a considerably contracted condition. 

 On opening the mantle, the position of the shell was found to 

 be 5 mm. from the posterior extremity of the animal and on 



Fi-s. 1. 2, o, Philomycm caroh'nianus (Bosc), Hudson, Ohio. 

 Fig. 4, P. rush!., n. sp. 



tho right side. It is of a light, horn color, transparent, very 

 iridescent, thin, delicate, wrinkled. It measures .5 mm. in 

 : no tli and .25 mm. in width. In appearance it greatly re- 



