DIAGNOSES 



ov 



KETV FORMS OF MOLLUSCA 



COLLECTED BY Col. E. JEWETT 

 ON 



THE WEST TROnCAL SHORES OF NORTH AMERICA. 



BT 



PHILIP p. CARPENTEPt, B.A., Pn.D. 



Rissoina expansa. 



Jt. testa mngna, lata, tenuisculpta, alba, nitente, subfliaphana; 

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

 niamillato ; norm, v., plaiiatis, suturis distinctis ; costulis radiunti- 

 bus circ. xxiv., obtusis, baud extantibus, intcrstitia sequantibus, 

 periphcriam versus evanidis ; circa basim productani striis spiralU 

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

 labro subaiitice producto, varicoso, antice et postice alte siuuato , 

 labio calloso. Long. '3.5, long. spir. "18, lat. '17 poll., div. 30°. 



Hab. Mazatlan (teste Jewel t). 



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 hamata. 



JH. testa carneo-aurantiaca, satis turrita, marginibus spirac excurvatis j 

 anfr. nucl. ii. globosis, tenuissime cancellatis, apice mamillato ; nona> 

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

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

 longatam continuis ; interstitiis concavis ; lirulis spiralibus filosis, 

 distantibns, supra costas transeuntibus, in spira iii.-iv. ; apertura 

 eubelungata, quasi hamata, intus Isevi, intense culorata: labro 



293 



