MAZATLAN UNIVALVES 435 



lot. '027, div. 18. Mr. Hanley however found four specimens, 

 each with five whirls, the largest of which measures ' 113 by '037. 

 Hal. Mazatlan ; extremely rare, off Spondylus ; L'pool 



Havre Coll. 



Tablet 2008 contains the youngest sp. ; and an adult, present- 

 ed by S. Hanley, Esq. 



538. DUNKERIA CANCELLATA, n. S. 



D. t. junior e efflisd, rufo-fuscd, anfr. normalibus ii et dimidio, 

 valde tumentibus, vix attingentibus, superne angulatis ; vertice 

 nucl&oso tumente, helicoideo, anfr. ii. verticaliter sitis ; lirulis 

 plurimis transversis acutissimis, et spiralibus minoribus elegan- 

 tissime cancellatd ; labro angulato ; labio rimulam umbilicalem 

 circumeunte ; plica columellari nulld. 



This exquisitely beautiful young shell looks like an elongated 

 Cancellaria without plaits ; it is shouldered as in C. goniostoma. 

 The sinistral apex is very prominent. When adult, it must be 

 of surpassing elegance. Long.'ffiS, long. spir. '02, lot. '02, 

 div. 15. 

 Hob. Mazatlan ; 1 young sp. off Spondylus ; L'pool Col. 



Tablet 2009 contains the specimen. 



539. DUNKERIA INTERMEDIA, n. s. 



D. t. albd, elongatd, tenui : vertice nucleoso maxima, anfr. iii. 

 helicoideis, verticaliter sitis, prominentibus, apice conspicuo, 

 marginibus spires superantibus ; anfr. primis normalibus*con- 

 vexis, dein subplanatis ; striis spiralibus omnino ornatd, tenui- 

 bus, obtusis, git-arum circiter vii. in spird apparent; striulis 

 tenuibus minoribus] iransversis evanescentibus vix decussatd ; 

 inter dum, lirulis evanescentibus irregularibus ; basi subelongatd; 

 aperturd ovali ; columelld vix contortd. 



This species is described, although from a single young 

 specimen and a broken adult, in consequence of its aberrant 

 sculpture, which is more appropriate to Aclis, while the shape 

 of the aperture is characteristically Chemnitzian. The trans- 

 verse ridges are only represented, in the young shell by very 

 faint threads, most conspicuous at the sutures, while the spiral, 

 somewhat flattened lines are prominent. The young specimen 

 has only 3 normal whirls, and measures long. '055, lat. '027, 

 div. 12. The adult, which has lost the lower whirls, has the 



