102 THE NAUTILUS. 



blances. Its principal differences from P. carmelita are the posses- 

 sion of the two teeth (carmelita never exhibits a vestige of teeth) 

 and the adnate peristome. These two features, however, bring it 

 nearer to P. si'bacuta, but the sculpture, the deflection of the last 

 whorl (or rather the descending), the color of the peristome and 

 teeth, and the generally less inflated appearance of the shell remove 

 it also from that species. It appears as if thrown in between carme- 

 lita, subacnta and acuta to exemplify the sportive tendencies of the 

 very variable group to which they all belong. 



Figures 1 and 2 are from the type. Figure 3 represents a speci- 

 men approaching subacuta. 



PLEUUODONTE (PI.) SOROR Fer. var. PERACUTA, n. var. PI. VI, 

 figs. 4, 5. 



Same in size as the type, but the shell is more depressed, the base 

 less regularly convex and the outline of the spire is more conoidal. 

 The periphery of the last whorl is much pinched and spread out into 

 a wide, flat, knife-like carina. The base is somewhat convex below 

 the periphery, then compressed laterally inward from it and inflated. 

 The umbilicus is uncovered ; the aperture subtriangular, narrowed 

 transversely and forming an acute angle at the right side. A few 

 examples are unicolored brown with the epidermis dull and flaky as 

 in some specimens of P. cara, but by far the greater number of 

 specimens are banded with dark and white, as in the type of soror, 

 on the spire, and the periphery of the last whorl is white. The 

 bands do not stop, as in the type, half way up the spire, but. extend 

 to the very suture line of the first apical whorl. The color of the 

 shpll (or of the bands) is not so intense, or pure or lustrous white as 

 in the type. The shells somewhat resemble small banded forms of 

 P. peracinissima, but they have the teeth of soror. A specimen re- 

 ceived from Chitty is marked "soror?." From Lower Maysfield in 

 in the Parish of St. Elizabeth. 



A NEW SPECIES OF VOLUTOMITRA. 



BY W. II. DALL. 



This genus has long rested on its typical species, the Mitra grbn- 

 Icuidica (Beck) Mo'ller of the Arctic Atlantic Seas. The discovery 

 of another species, therefore, possesses somewhat more than the ordi- 

 nary interest. 



