from the West Coast of North Ammica. 5 



329 b. Biitium (? var.) esuriens. 



B. testa B. filoso simili, sed multo minore, graciliore, interdum vald 

 attenuata ; sculptura testse juii. ut in B. filoso, testae adultce sub 

 obsoleta; interstitiis baud insculptis. Long. '3, long. spir. -21 

 lat. -11, div. 25°. 



Hab. Sta. Barbara {Jewett) ; Neeah Bay {Swan) ; Monterey 

 (Cooper). 



334. Bitiium fastigiatum. 



B. testa parva, gracili, pallide rufo-cinerea, marginibus spirae vix 

 excurvatis ; anfr. nucl. iii., Isevibus, tumidis, apice acuto; norm, ix., 

 planatis, suturis alte impressis ; anfr. primis iii. carinatis, postea 

 costis radiantibus circ. xiii., obtusis, satis extantibus, ad suturas 

 interruptis, interstitiis undatis, liris spiralibus iv. in spira se mon- 

 strantibus, costas undatim superantibus, quarum antica in testa 

 jun. plerumque extat; anfr. ultimo parum contracto, basi elongata. 

 liris spiralibus vi. contiguis ornata ; apertura gibbosa; labro 

 acuto, interdum varicoso, antice angulatim emarginato ; labio 

 tenui. Long. '25, long. spir. 'IQ, lat. '09, div. 20°. 



Hab. Sta. Barbara [Jewett). 



Genus Amphithalamus*. 



Testa Rissoidea, nucleo maguo ; apertura labio producto, labro 

 subpostice juncto, subito in adulta contracto. 



355, Amphithalamus inclusus. 



A. testa minuta, lata, solidiore, pallide rufo-fusca ; vertice mamillato ; 

 anfr. nucl. uno et dimidio, quoad magnitudinem perinagnis, nii- 

 nutissime et confertissime spiraliter et radiatim striolatis ; anfr. 

 norm, iii., Isevibus, subplanatis, suturis impressis ; basi subangulata ; 

 costa peripherica rotundata, baud extaute, interdum in spira se 

 monstrante ; costa altera circa regionem pseudo-umbilicarem ; labro 

 acuto, haud contracto : labio testa adolescente normali, dein a 

 pariete separata, sinum posticum suturam versus formante, t. adulta 

 valde separata, regionem quasi umbilicarem magnam formante; ad 

 labrum subito fere perpendiculariter, subpostice juncto : operculr 

 tenuissimo. Long. '04, long. spir. "02, lat. '03, div. 60°- 



Hab. Sta. Barbara {Jewett); S.Diego {Cooper). 



This very remarkable little shell bears the same relation to 

 Rissoa that Stoastoma does to Helicina. The peritreme resem- 

 bles a figure ^ inverted^ as on the face of the type. In the dis- 

 proportionate size of the nuclear whorls it resembles Vitrinella. 



373. Drillia mcesta. 



D. testa acuminata, Irevi, dense olivaceo-fusca, epidermide Isevi ad- 

 hserente induta ; anfr. nucleosis ?... (decoUatis) ; norm, viii,, parum 



* Th. dix<p\, BoKa/jios, having a chamber on both sides. 



283 



