200 CALIKOUNIA ACADKMY OF SCIENCES. 



163. Pleurotoma perversa Guhh. 



PUiirotoma />rrvrna C.Miu, I'loc. Cal. Acad. Sci., \'(.l. Ill, 1S65, p. iS;,; Pal. Cal., \'ul. H, i)|i. 6, 



73, PI. 1, fig. 10,1869. CooPKK, 7lh Ann. Ri\n. (';il. .St. Mln.. iS.SS, p. 260. 

 Siircuhi perversa, Gahu, Tkyon, Man. Cotuli., \'i)l. \'I, ]>. 239, PI. \'l, tig. 79, 18S4. 



Shell small, sinistr.il, elong.ito, sU-nikr; whorls fight lo t-lovcn, convex; surface smooth 

 e.xcept lor fine incremental lines which are conve.xly angulaled posteriorly a little above middle ol 

 whorl; suture deeply impressed, distinct; aperture elongate-ovate; outer lip arcuate anteri<4rly; inner 

 lip incrusted; columella smooth; posterior sinus prominent; anterior sinus long, narrow. 



/^/mtnsiaiis. — Long. 42 mm.; lat. 11.5 mm.; body-whorl 21 mm.; aperture, including canal, 

 16 mm.; iletl. iS degrees. 



I)i.stiiiii'iii-li:ililc rroiii (illuT iiiciiilicrs (if (liis t;imily hy beinfj sinistral. 



CoMimoii ill tlio Pliuceiic and lower San Pedro scries at Duadmaii Island; in 

 lower San Pedro series at San Pedro; and rare in the upper San Pedro series at 

 Deadman Island, San Pedro, ami Los Cerritos. Coninion in upper San Pedro series 

 at Crawfish George's. 



Living. — Vancouver Islaiul to Catalina Island (Cooper). 



Pleistocene. — Santa Barlinra to San Pedro (Cooper): San Pedro (Arnold). 



Pliocene. — San Pedro (Arnold). 



Subgenus Borsonia Btllanli. 

 Shell tusil'Driii; with a plication upon the midtlle of the coIumk-H.i. 

 Pli'urotnnin pijrenaica Koualt i>^ a cliarMctcristic species. 



164. Pleurotoma (Borsonia) bartschi, sp. no v. 



Platk V, Fio. 7; TiatkIX, Fh;. 1. 



Shell small, fusiform, elongate; apex obtuse, mammilliform; whorls seven, angulated near 

 middle; body-whorl less angulated than those of spire; anterior portion of whorl ornamented with 

 about twelve oblique, transversely elongated nodes, wliich reacli their greatest prominence on the 

 angle of the whorl; body-whorl sometimes smooth and sometimes nodose; posterior portion ot whorl 

 rt.it and smooth except for incremental lines; incremental lines fine, oblique, and angulated convexly 

 posteriorly on upper portion of whorl; suture deeply appressed, distinct; aperture elongate-elliptical; 

 outer lip thin, arcuate anteriorly below posterior sinus; inner lip incrusted; columella nearly straight, 

 incrusted, with one sliarj) plication in middle of aperture; posterior sinus shallow; anterior sinus 

 prominent. 



Dimensions. — Long. lonim.; lai. 7 mm.; body-whorl 11.5 mm.; ajierture, including canal, 

 S.5 mm.; defl. 28 degrees. 



Distinguishable from B. dallii and B. Jioorcrl \)y the prominent nodes on the 

 whorls. Looks veiy much like Drillia torosa, but is easily distinguishable by the 

 plication on columella and more angulated body-whorls. Pronounced a new species 

 by Dr. Dall. Specimens of Borsonia barlschi in the State Museum collection of 

 fossils at Berkeley are labeled "Drillin moisia." 



