from the West Tropical Shores of North America. 399 



Siphonalia fuscotincta. 



S. testa minima, turrita, albida, apicem versus fusco tincta ; anfr. 

 nucl. ii., compactis, subplanatis, apice mamillato ; norm, iv., con- 

 vexis, suturis impressis ; costis radiantibus rotundatis, tumentibus, 

 basim versus evanidis, interstitiis undulatis, subeequantibus ; lirulis 

 crebris spiralibus, costas superantibus ; apertura pyriformi, in 

 canalem brevem apertum contortum producta ; labro acuto ; la- 

 bio haud conspicuo ; columella canalem versus valde contorta. 

 Long. -17, long. spir. -1, lat. -08, div. 32°. 



Hah. Sta. Barbara (Jewett). 



The unique specimen is like a minute edition of Siphonalia 

 Kellettii, but does not accord with the young of that or of any 

 other species known in the region. It is probably not mature. 



XLI. — Diagnoses of new Forms of Mollusca collected by Col. E. 

 Jewett on the West Tropical Shores of North America. By 

 Phtlip P. Carpenter, B.A., Ph.D. 



Rissoina expansa. 



R. testa magna, lata, tenuisculpta, alba, nitente, subdiapbana ; 

 marginibus spirse parum excurvatis ; anfr. nucl. laevibus, vertice 

 mamillato ; norm, v., planatis, suturis distinctis ; costulis radianti- 

 bus circ. xxiv., obtusis, haud extantibus, interstitia sequantibus, 

 peripheriam versus evanidis ; circa basim productam striis spirali- 

 bus expressis ; medio lsevi ; apertura valde expansa, semilunata ; 

 labro subantice producto, varicoso, antice et postice alte sinuato ; 

 labio calloso. Long. *35, long. spir. '18, lat. '17 poll., div. 30°. 



Hah. Mazatlan (teste Jewett). 



This fine species is the largest known in the fauna. It most 

 resembles R. infrequens, C. B. Ad., which was described from a 

 dead shell. 



Mangelia ha mat a. 



M. testa carneo-aurantiaca, satis turrita, marginibus spirse excurvatis ; 

 anfr. nucl. ii. globosis, tenuissime cancellatis, apice mamillato ; norm, 

 vi., subelongatis, in spira tumentibus, subangulatis, suturis impressis ; 

 costis radiantibus x.-xii., aeutioribus, validis, circa basim pro- 

 longatam continuis ; interstitiis concavis ; lirulis spiralibus filosis, 

 distantibus, supra costas transenntibus, in spira iii.-iv. ; apertura 

 subelongata, quasi bamata, intus leevi, intense colorata ; labro 

 acuto, dorsalicer varicoso, postice valde sinuato. Long. "2-1, long, 

 spir. -13, lat. -1, div. 25°. 



Hah. Panama (teste Jewett). 



This very beautiful species is easily recognized by the varicose 

 lip, sloping off to a sharp edge ; by the deeply cut posterior 

 notch, giving the smooth mouth a hooked appearance ; by the 



