MAZATLAN UNIVALVES 435 
lat. °027, div. 18°. Mr. Hanley however found four specimens, 
each with five whirls, the largest of which measures *113 by *037. 
Hab.—Mazatlan ; extremely rare, off Spondylus; L’pool & 
Havre Coil. 
Tablet 2008 contains the youngest sp. ; and an adult, present- 
ed by S. Hanley, Hzq 
538. DUNKERIA CANCELLATA, N.S. 
D. t. guniore effusd, mf fusca, anfr. normalibus ii et dimidio, 
valde tumentibus, via attin gentibus, superne angulatis ; vertice 
nucleoso tumente, helicoideo, anfr. u. verticaliter sitis; lirulis 
plurimis transversis acutissimis, et spiralibus minoribus elegan- 
tissime cancellaté ; labro angulato ; labio rimulam wmbilicalem 
circumeunte ; plicd columellari nulla. 
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. ‘038, long. spir. 02, lat. *02, 
div, 15°. 
Hab.—Mazatlan; 1 young sp. off Spondylus; ZL’ pool Col. 
Tablet 2009 contains the specimen. 
539. DUNKERIA INTERMEDIA, 7. s. 
D. t. albé, elongata, tenui: vertice nucleoso maximo, anfr. ii. 
helicoideis, verticaliter sitis, prominentibus, apice conspicuo, 
margimbus spire superantibus ; anfr. primis normalibus con- 
vexis, dein subplanatis ; striis spiralibus omnino ornatd, tenwi- 
bus, obtusis, quarum circiter vu. in spird apparent; striulis 
tenuibus minoribus transversis evanescentibus via decussata ; 
interdum, lirulis evanescentibus irregularibus ; bast subelongaté; 
apertura ovali ; columelld vix contorta. 
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, hag the 
