MAZATLAN TJXIVALTES 245 



Hah.— 'Mazatlan ; extremely rare, off Spondylus and Cliama ; 

 L'pool Col. 



Tablet 1157 contains the perfect specimen, and the youngest, 

 with, the rugse conspicuous. The other ts\'0 specimens found 

 were intermediate between these extremes. 



307. PVlTEIXELLA ANNTTLATA, n. S. 



?V. t. subglohosd, solidiore, opaca, alha, anfractihus iv. et 

 triente ; spird liaud depressd, Icevi ; carina spirali ad peri- 

 pheriam conspicud, rotundatd ; carinis duahus minorihu^, acv.ti.^, 

 quarum altera umhilicum satis magnum definat, altera inter- 

 media est ; aperturd suhrotundatd , a carinis suhangulatd, anfr. 

 penult, parum attingente ; suturd suhimpressd ; striis -nonnvdli.^ 

 spiralibus in spiram monstrantihus. 



This shell is somewhat solid and globose for the genus ; and 

 the nuclear portion not being clearly defined in the solitary 

 specimen found, its position is doubtful. It is easily recog- 

 nised by the rounded, annular keel on the periphery, with 

 two somewhat sharp ones on the base, the latter bounding the 

 umbilical region. Long. •027, lat. -052 by '047, div. 150". 

 Bai.— Mazatlan ; 1 sp. off" Chama ; Upool Col. 



Tablet 1158 contains the specimen. 



308. VlTEIXELLA CIXCTA, W. S. 



V.[t. subglohosd, alba, anfractihus iv. tumidis ; carinis duahus 

 majorihu-s, aeutis, haud valde prominentihu^, haud distantibv.s. 

 v.troque latere periphericB plajiatcB spiraliter cingentihus ; duahus 

 quoque in hasi minoriljus ab umhilico profundo, haud expanso, 

 et peripherid cequidistantibus ; spird suhplanatd ; striis passim 

 spiralibus ; aperturd a carinis angulatd, anfr. penult, parum 

 attingente ; regione inter umbilicum ipsum et carinam profunde 

 concavd ; anfractu ultimo parum declivi. 



The two principal keels are much closer and less prominent 

 than in V. bifrontia. In the base it resembles V. annulata, 

 but the spiral portion is quite different, being flattened, with 

 verv' numerous spiral striae. The whirls do not enlarge rapidly. 

 The umbilicus itself is somewhat narrow, with a broad funnel 

 leading down to it from the nearest keel. The labium is some- 

 what reflexed over it. Long. '02, lat. "034 by '028, div. 170. 

 Hab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



Tablet 1159 contains the specimen. 



