1899.] NATURAL SCIENCES OF PHILADELPHIA. 147 



No. 79,015. Turbonilla compsa, new species— not T. flavocincta C. B. Adams. 1 speci- 

 men. 

 No. 72,056. Turbonilla pupoides d'Orb. 1 specimen. 



Maldonado Bay, Uruguay, three to six fathoms. Dr. William 

 R. Rush, 1897. 



No. 70,537. Turbonilla atypha, new species. 2 specimens. 



No. 70,535. Turbonilla Rushii, new species— not T. interrupla (Totten). 1 specimen. 



TURBONILLA. 

 Risso, 1826 (sensu extenso). 



The genus Turbonilla is here taken in its most extended sense to 

 include all species having a more or less elongated form, consisting 

 of few or many planulate or more or less convex, sometimes shoul- 

 dered, whorls, always ornamented with more or less prominent, 

 transverse ribs, and always having a i-eversed, flattened or project- 

 ing nucleus consisting of about 1^ to 3 whorls, tilted from trans- 

 verse to the axis to more or less oblique. Intercostal spaces smooth 

 or crossed by more or less distinct, incised, sometimes raised, spiral 

 lines which often also appear on the base, which varies from short, 

 little rounded (the body-whorl subangulated at the periphery), to 

 elongate and well-rounded. Aperture varying fi'om subquadrate 

 with straight pillar-lip, to elongate-ovate, well-rounded and pro- 

 duced below, with curved pillar-lip. Peritreme generally discon- 

 tinuous, rarely continuous; inner lip more or less thickened and 

 reflected, usually with a plication or fold, often invisible exter- 

 nally; outer- lip almost always thin, seldom thickened. 



In its most restricted sense the genus was proposed by Risso, 

 1826, from Leach's manuscript, for Turbo lacteus Linne, as the 

 type, of which Helix elegantmima JNIontagu is now considered a 

 synonym. This species has an elongated form; an obliquely tilted 

 nucleus of about 1|- flattened whorls ; well developed transverse 

 ribs ending at the periphery of the body-whorl, with smooth, 

 intercostal spaces; base smooth; aperture somewhat elongaled; 

 pillar-lip straight, thickened and reflected. 



Many species have, however, come to light which not only possess 

 these chai-acters in a more or less marked degree, but have others in 

 addition. This has rendered it necessary to introduce new limits for 

 the genus. Many additional names have been proposed by various 

 authors (Carpenter, 1855-7; Monterosato, 1884;Sacco, 1892, and 

 others) for these new divisions, which need much careful study and 



