NO. 12 STRONG AND HERTLEIN : MARINE MOLLUSKS 209 



fold on the columella. This character also separates it from the genus 

 Niso which contains some species which are quite similar in general 

 appearance. It may belong to some subgenus of Odostomia not previ- 

 ously reported from the west coast but seems to fit better in the sub- 

 genus Evolea than in any of the other subgenera known from the west 

 coast of the Americas. 



Triphora palmer! Strong & Hertlein, new species 

 Plate 20, Fig. 1 



Shell sinistral, regularly elongate-conic, light brown ; nuclear whorls 

 6, the first 2 smooth, lighter than the balance of the shell, the 4 follow- 

 ing whorls sculptured with 2 spiral cords and fine axial ribs of which 

 about 30 appear on the last whorl; of the 2 spiral cords one is on the 

 middle of the whorl and the other half way between it and the base; 

 postnuclear whorls 7, sutures distinct; spiral sculpture on the early 

 whorls consisting of 2 nodulous cords, of which one is at the summit 

 and the other a little above the suture; beginning at about the third 

 whorl a median, nodulous, spiral cord begins to develop and soon equals 

 the other 2 in strength ; axial sculpture of slender ribs connecting the 

 nodules of the spiral cords and extending into the sutures; of these, 20 

 appear on the early whorls, gradually increasing to 24 on the last whorl ; 

 below the median spiral cord these ribs are nearly vertical, while on the 

 upper part of the whorl they are retractive, the degree of angulation 

 at the crossing of the median cord varying at different places on the 

 shell; on the upper spiral cord the nodules are well rounded, while on 

 the median and lower cord they slope more abruptly posteriorly than 

 anteriorly; the space inclosed by the spiral cords and axial ribs form 

 well impressed, square pits; periphery of the last whorl marked by a 

 smooth cord, below which, on the base, are 2 similar and nearly equally 

 strong and equally spaced spiral cords, the interspaces crossed by feeble 

 extensions of the axial ribs; aperture oval, strongly channeled anteriorly; 

 outer lip thin, the edge partly broken in the type; columella short, 

 twisted; body covered with a thin callus. The type measures: length, 

 3.2 mm; diameter, 1.1 mm. 



Holotype: No. 747 (Calif. Acad. Sci. Paleo. Type Coll.), from 

 Loc. 27,228 (C.A.S.), dredged in from 3 to 9 fms. off Taboga Island, 

 Panama. L. G. Hertlein collector. Forty additional specimens were 

 dredged in the same locality and 16 specimens dredged in Bahia Honda, 

 Panama. 



