8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



ture consists of fine threads, which in the sinus portion near the 

 summit of the early turns are about as strong as the spiral threads 

 anterior to this, but on the later whorls these spiral threads become 

 less strongly developed, while those anterior to it increase in strength. 

 The anterior portion of the whorls on the later turns are marked 

 by rather coarse, definitely spaced threads, between whichj finer spiral 

 threads are present, varying in number from one to four. This fine 

 sculpture, combined with the lines of growth, gives a reticulated pat- 

 tern to the spiral grooves between the spiral cords. Base short, well 

 rounded, marked like the anterior portion of the spire. Columella 

 very long, slender, marked by numerous slender, more or less equally 

 spaced spiral threads, which become somewhat enfeebled near the 

 tip. Between these stronger threads an occasional slender spiral thread 

 is present. Aperture tear-shaped with a very long anterior channel. 

 The posterior channel broad and deep, immediately below the sum- 

 mit. The inner lip smooth, appearing as if excavated below the sur- 

 face of the sculptural portion of the shell. 



Type. — U.S.N.M. no. 425356, collected at station 35 in 180 to 80 

 fathoms between latitude i8°23'4o" N., longitude 67°i6'45" W. and 

 latitude i8°24'45" N., longitude 67° I4'i5" W. It has eight and one 

 quarter whorls remaining and measures : Length, 71. i mm; diameter, 

 20.4 mm. 



A younger specimen, a topotype, U.S.N.M. no. 430653, has nine 

 whorls remaining and measures : Length, 56 mm; diameter, 16.7 mm. 



I have seen nothing in our turritid collection that compares with 

 this group. 



POLYSTIRA Woodring 



The genus Polystira was created by W. P. Woodring in 1928 ' 

 for certain large West Indian turritids. He named the largest of the 

 recent species, generally known as Pleurotoma albida Perry, as type. 

 Unfortunately, the moUusk so designated is not Pleurotoma albida 

 Perry, which Perry states ^ " is frequently found at New Zealand 

 and Lord Howe's Island." Perry's figure 4, plate 32, of this species 

 does not agree with the West Indian material. It clearly resembles 

 certain shells from North Australia in the collection of the National 

 Museum. The name is, therefore, not applicable to the West Indian 

 shell, which will have to carry the next available designation. 



* Miocene mollusks from Bowden, Jamaica, pt. 2, p. 145, 1928. 

 ^ Conchology or the natural history of shells, London, 181 1. 



