Alii:n\ M T \. 

 Shell with dist.-int ribs. l:itcr:ill\ compre-ed t nbei <!- ..n t he 



e;inn:i; surface smooth, polished. 



iin <>f riidi/ioiit not li\iiii; in Mrditi-iTiiiH'im > 

 N<>. Atlantic Ocean 



\ figure the typical JL fa'ana (fig. loi).from Ad.-nn- :md Keeve. 



Vov.-iire S:iiu:ir:inu-. :nul tlir eared form ( A. '/n<llti. Dilhv.. ti--. 

 KM). KI-J). witli its :niiin:il. 



A. OWKMI. Ad.-iins mid lli'fvc. IM. M\. li->. In;; 105; pi. IT. 

 fiirs. lor,. 107. 



Tlir rils ;n-c soinc\vli:it (dosci 1 Mini the t uhcndc^ <>n the c:iriii;i' 

 :uv sh:iri>ci- ;iiid not Laterally compressed :is in .1. />/V///x; the snr- 

 t:icr is shMiiTcciHMl. 



S. Atlantic Ocean. 



A. cornufa. ( 1 onr:ul (li.u's. KM. lO.V). is ;in c;n-i-(l form of the 

 siMiu- spi'eies. A. <Ii*i><ir. ( 1 onni(l (lOU. l07).diHei-s only in the 

 nnnsunl (U'veloinient of some of the Intend e:mn:d t nherele>. 

 Mild in :i portion of the l>Mck lu'in<>- t ulxTciihite neither of them 

 specific characters. 



A. Co.MtADi. I'ni-kinson. 



Kilis rMther dist;uit. not fnrcMte. lonjj nnd short MlteniMtely. 

 portion of the l;i(dv studded with SHIM!! tultercles ; tnltei'des on 

 Miiterior Mini posterior thirds of cMriiue sinnll. ne:irly olisolete : 

 on the middle third of eMch c;irin;e. seven very K-iro-e t nl>eivle<. 

 liroMd Mt the bnsc'. InterMlly coniprcssiMl. Aperture Mii^led. 

 spineless. SnrfMce sliMu'reened. 



This species IIMS never been figured; it is not MppMrently \cr\ 

 distinct from A. On-cnii. :ind perliMps. ly its hiternlly coni- 

 pressi'd tnhercles. HIMV unite tliMt species with J. hitin*. 



New Nantucket, Pacific Ore 



A. KoniiANA. Dnnker. PI. 47. lio- s . H)S HO. 



Hitlers from A. hianx in the ribs beinir elscr :ind le-- prom- 

 inent ; from A. Otrr.nii. in the tubercles on the c:irin;e beinu' but 

 little prominent and IhiMlly becoming obsolete, and in the snrlMce 

 of the shell bein^ polished. Troliably nil these forms should be 



referred to A. hian*. 



r M ,>*,- - 

 IS 



