74 BULLETIN OF THE 



bands of olive-green color, polished, narrow and resident in the epidermis, but 

 visible through the translucent shell in the aperture. These bands sometimes 

 fill the spiral channels ; sometimes there are two olive bands separated by a 

 pale one between two of the elevated spirals ; sometimes the fiat tops of the 

 spirals are thus colored; in general there will be about ten of these olive stripes 

 on the last whorl. They extend only over the whorl, the pillar from its 

 junction with the body is destitute of them, and, when fresh, is of a delicate 

 rose color, which is apt to fade. This white or rosy rostrum contrasts vividly 

 with the striped body and spire. Lon. of shell, 19.0; of spire, 8.5; of white 

 rostrum, 8.75; max. lat. of shell, 4.75 mm. 



Habitat. Off Havana in 80-127 fms., Sigsbee; Station 143, off Saba Bank, 

 in 150 fms., bottom temperature 63°.2 F. 



This may be, as Mr. Tryon claimed when it was shown him, a variety of 

 P. albida, but I incline to the belief that it is a good species. 



Pleurotoma periscelida Dall. 



Plate XXXII. Fig. 2. 



Shell stout, fusiform; covered with a straw-colored epidermis; elaborately 

 sculptured; ten whorled, exclusive of the nucleus; spiral sculpture consisting 

 of (1) a cord at first rounded and irregularly constricted at short intervals, 

 later flattened with numerous transverse waves and indentations ; this band be- 

 comes gradually wider, has two small grooves along its center, and at the sides, 

 especially the sutural side, it overhangs the channels on each side of it; from 

 the first this band conceals the suture, toward the end of the last whorl it be- 

 comes less prominent and descends slightly; (2) a broad elevated band grooved 

 centrally and covered with twin nodules in pairs one above the other, which 

 on the later whorls are somewhat reniform ; this band represents the fasciole 

 or pathway of the square-cut anal notch; (3) in the channel between the two 

 last are two small, elevated, rounded nodulous cords; (4) in front of the fas- 

 ciole and on the base of the last whorl are four or five strong spirals, and be- 

 tween these and in front of them on the canal are numerous smaller ones, all 

 crossed and roughened by the transverse ridges of growth; one or two of these 

 spirals are visible on the whorl before the last, the earlier ones not showing 

 any of the basal spirals; transverse sculpture of coarse elevated incremental 

 lines more or less visible over the whole shell; aperture rather wide, canal 

 narrow and slightly curved ; outer lip with a deep notch squared at the bottom, 

 then strongly arched forward, later contracted for the canal; margin simple, 

 sharp; inner lip white, smooth, simple, slightly excavated; inside the outer lip 

 are six or eight strong lira falling short of the margin; pillar nearly straight, 

 attenuated and twisted in front, making the end of the canal flare a little; there 

 is no umbilical trace. Lon. of shell, 40.5 ; of last whorl, 27.0; of aperture, 22.5; 

 max. lat. of shell, 15.0 mm. Nucleus defective in the specimens. 



Habitat. U. S. Fish Commission Station 2143, living in 155 fms., mud, near 



