SPIRAXIS. 11 



interstices. Whorls 6%, very convex. Aperture ovate, tire 

 outer lip arching strongly forward in the middle (fig. 3), 

 thin and unexpanded. Columella very short, excavated above, 

 somewhat straightened in the middle, curving below into the 

 basal margin. Length 2.5, diam. 0.7, length of aperture 

 0.7 mm. 



Jamaica (Adams coll., Amherst College Mus.). 



Bulimus minimus C. B. ADAMS, Contrib. to Conch, no. 2, 

 p. 28 (October, 1849). PFR., Monogr. iii, p. 441. REEVE, 

 Conch. Icon, v, pi. 84, f. 623 (bad), (Dec. 1849). Not Buli- 

 mus minimus Brug., Encycl. Meth. p. 310 (1789). 



The systematic position of this peculiar little shell" is un- 

 certain; it may possibly be an operculate. From the struc- 

 ture of the columella it is surely not -an Opeas, and I have 

 placed it with the preceding species as a temporary expedient, 

 until living specimens can be studied. In his description 

 Adams mentions spiral striae, which I did not see when draw- 

 ing the figures; yet as I have not the specimen at hand for 

 renewed examination, I cannot deny their presence. The 

 above description is from my notes on the type. 



Genus SPIRAXIS C. B. Adams, 1850. 



Spiraxis AD., Contribution to Conchology no. 6> p. 87 

 Ma>rch, 1850, for S. inusitata, S. aberrans and S. costulosa. 

 SMITH, Journ. of Conch, viii, p. 235 (type S. inusitata). 



Not Spiraxis Newberry, Ann. N. Y. Acad. Sci. iii, p. 219, 

 1884, for Spiraxis major and S. randalli Newb., based upon 

 coprolites of the Chemung shark Cladoselache ; cf. Trans. 

 N. Y. Acad. Sci. xiii, 118. 



Small, turiiite or long-ovate Oleacinidcz, with the columella 

 ascending in a spiral curve which projects into the aperture 

 more or less, and at the base curves into the basal lip without 

 truncation or excision, sometimes having a -callous lamella 

 superposed upon the convex columella. Embryonic whorls 

 smooth, or after the first whorl, striate. 



Type S. inusitata Ad. Distribution, Antilles >and Mexico. 



Spiraxis is related to Pseudosubulina and Varicella. It 

 is apparently a very old phylum, which was evolved 



