422 MAZATLAN TTNIVALVES 



and a broken adult sp. shewing the lip. This, when perfect, 

 must have had 7 normal whirls. [One of Mr. Hanley's speci- 

 mens, though small, has the peritreme continuously developed, 

 and shaped as in Chr. communis.] 



509. Cheysallida Reigeni, n. s. 



Chr. t. forma et sculptura " Chr. telescopio" simulante, sed 

 had rotundata, vertice micleoso ut in "Chr.fasctatd" celato. 



One specimen onlj-, somewhat broken and immature, was 

 found of this species, which is named in remembrance of 

 the gentleman to whose almost unparalleled zeal we owe the 

 immense collection, a ver\' small part of which is here described. 

 A minute umbilical chink is seen, probably from a fracture of 

 the labium over one of the basal striae. Long. "057, long. spir. 

 •034, lat. -028, div. 26". 



Hah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



Tablet 1979 contains the specimen. 



510. Cheysallida effusa, n. s. 



Chr. t. avoided, albidd, effusd ; marginibtis spires excurvatis ; 

 vertice nucleoso ?... ; anfr. ?iv. parum planaiis, liruli^ spiraUhus 

 acutis viii. cinctd, quaruin iv. in spird, a lirulis transversis, sihi 

 parallelis, in lineis declivihus ad veriicem ascendentibus, acutior- 

 ihus, deciissatce, ad intersectiones nodosa ; una extans suturam 

 continuat ; alterce in basin valde produciam ; sfriulis iii. ad 

 regionem umhilicalem ; lirulis transversis juxia siduram im- 

 pressam declivihus, evanescenfibus ; intersiitiis basalibus latis 

 distanter tenuissime decussatis : labro ad basin valde sinuato, 

 effUso ; plica celatd, patv)d, acuta. 



Of this species, the most delicately sculptured in the group, 

 only one not quite matiu'e specimen was found, the vertex of 

 which is imfortuuatel}- injured. The transverse riblets are 

 parallel to each other, not to the margins of the whii'ls, and 

 vary in number accordingly. The structure of the sutitral 

 groove is as in Chi-, telcscopiiim. Long. '09, long. spir. '054. 

 lat. -038, div. 20". 

 Hah. — Mazatlan ; 1 sp. off Chama ; L'pool Col. 



Tablet 1980 contains the specimen ; also a very yoimg shell, 

 with a sunken apex, which might have developed into this 

 species or into a slender form of Chi\ fasciata. 



