140 AMERICAN JOURNAL 



narrow, with a straight or recurved canal anteriorly and a canal 

 ascending the spire posteriorly ; outer lip digitate, margin of 

 aperture smooth or transversely striate. 



Pterocera lambis, Lam., = Strombus lambis, Linn., is the La- 

 marckian type of the genus which thus includes the smooth lipped 

 forms placed under the subgenus Heptadactylus by H. and A. 

 Adams. 



Sub-gen. Millipes, H. and A. Adams. Margins of aperture 

 transversely wrinkled or corrugated. 



P. cJiiragra, P. multipes, P. elongatus, P. scorpio. The num- 

 ber of digitations or processes on the outer lip varies so much 

 that it is at best a poor character, and does not seem to pos- 

 sess more than a specific value. 



In the Cretaceous and Jurassic formations are many shells, 

 with all the characters called for in the commonly received defi- 

 nition of Pterocera, but having a peculiar ' facies ' of their own ; 

 they are usually smaller than the living species, differ in orna- 

 ment, and frequently have very long canals and lip-processes. 

 Except in general appearance, I can find no differences ; though 

 if we could study them with the same facilities for detailed ex- 

 amination that we have among the recent shells, we would 

 doubtless find some characters for a generic, or at least sub- 

 generic separation. One group of these, in the Cretaceous, I 

 propose to separate as a sub-genus. 



S. G-en. Phyllocheilus, Gabb. Plata 13, fig. 6. 



General form as in Pterocera ; outer lip with no digitations, or 

 small ones only ; inner lip expanded as a thin plate over the 

 front of the body whorl, and sometimes projecting beyond it 

 laterally ; both outer and inner lip deeply notched anteriorly 

 near the canal. 



fyc. : Tellina-arcinata, Tellina-virgata, tfc. ; Concha-longa-biforis, Con- 

 cha-longa uniforis, Concha-TfiKoPot •' and in p. 167 ' Musculus-polylepto- 

 ginglymus' under which remarkable generic name is given as the first 

 species l Arca-Noce.' According to the now fashionable transformation 

 of malocological nomenclature into a branch of archaeological research, 

 under pretence of justice to ancient writers, the hitherto universally un- 

 derstood designations of Lamarck, &c, must give way to such names as 

 the above; and if some other 'attempt' or 'little lucubration' of a 

 year's earlier date should be disinterred from now-fortunate concealment, 

 the modern ' Guides ' and ' Books of Genera ' will have to be re-written." 

 As will be seen by a reference, to the note to the genus Aporrhais, 

 if we wish to use the oldest name, we must call the present genus Apor- 

 rhais and not Harpago or Pterocera ; and in that case, Strombus bryo- 

 nia being the type, the smooth lipped species must bear the generic name 

 and those with corrugated apertures will thus go into the first subgenus. 



