DIAGNOSES 

 ov 



NEW FORMS OP MOLLUSCA 



COLLECTED BY Col. E. JEWETT 

 ON 



THE WEST TROPICAL SHOEES OF NOETH AMEEICA.; 



BY 



PHILIP p. CARPENTER, B.A., Ph.D. 



Rissoina expansa. 



Jt. testa magna, lata, tenuisculpta, alba, nitente, subdiaphana; 

 margiiiibus spirse parum excurvatis ; anf'r. nucl. Ifevibus, vertice 

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

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

 peripberiam versus evanidis ; circa basim productani striis spirali- 

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

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

 labio calloso. Long. "SS, long. spir. '18, lat, '\7 poll., div. 30°. 



Hab. 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 hamata. 



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

 anfr.nucl.ii.globosis,tenuissimecancellatis,apice mamillato ; norm, 

 vi., subelongatis, in spiratumentibus,subangulatis, suturis impressis; 

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

 longatam continuis ; interstitiis concavis ; lirulis spiralibus filosis, 

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

 subelongata, quasi hamata, intus Isevi, intense colorata; labro 



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