47l) SIKKKIAX TKOPICAL IMKU'F.NK F0SSI1,>=; DALL, 



initUllo of Mio \\ lioiK ahoNc wliicli tli»Mt> is only spiriil sciil|tluro; in iVont 

 of it tlu' whoil is iiKulvi'tl witli ;iboiil ci.uht promiiuMil loiindcd waxes 

 ov oltsi'urt' libs, with wi(h>r iiitorsp;i('('s, \\ liicli bccoiiu' obsolct*' on tlie 

 last halt' of tlio last whorl; spiral sculptnic of fine, sharp, niiuntoly 

 chaimollod iiK'isi'd linos with much wider, smooth, liat topped intoi'- 

 spaces; suture appressed; base constricted alxml tlie middle, sculj) 

 tnrt'd with more crowded incised liiu's; pillai' with a moderat*' callus; 

 Ion. of shell, oo; max. diam., 17 nnllimelers. 



One s})eeimen (^Mus. Ucj;. t7!U») presented b> l>r. Stimpson. 



This species is related to tlu> uioiip represt'uted by ('. ruhiittidii llruu., 

 C. (jiiiitaicion rhil., and ('. (cnndKni Phil., the second ol" which extends 

 itsran>i"e fr(>m the (laboon. ^^'cst .\fri«'a. to the rinlippiiu's. Lord Hood's 

 Island, and Japan, if authorities maybe trusted. The fossil is, how 

 ever, sulUciently distinguished from any of them by its form and sculp- 

 ture. The uroup at present is oidy I'cprcscnted in warm-temperate, or 

 subtropical waters. The specinuui described had been attacked by 

 (UioiKi betbre tbssili/.ation and nH)re or less pcrt'oratcd, l)eside sustain^ 

 in_u' tlu' loss of its ou1er lip. .V much smaller, but in nnin> respei'ts 

 sinnlar, species is found in tlu> ()ldcr Mioceiu' of I'Miuida. 



Diloiua (^Chlorodilonia^ luderata ii. a 



rinli- i.\ 1, Ii):;. ;>. 



Shell snmll, turbiniform. rude, with little nacre, of about tour wlnn'ls; 

 whorls rtuunled, suture ai)i)ressed and sliohtly constricted, sculpture 

 only ol'rather rude lines of <iTowth ; surt'ai'c com]>osc(l of a dark shell 

 layer, with obsiau'e indications of si)iral liui's of lighter color; base lull, 

 slightly llattened, a narrow impressed area around the und)ilicus, which 

 is bandy perforate and nearly eoxcrcd by a snmll callus; aperture 

 rounded: pillar short, I'oncave. endinj;' in a snndl, low, narrow, tooth- 

 like prominence; tliroat smooth. Alt. of shell loj max. diam. of base, 

 13; nun, diam.. ll.."»0 millimeters. 



Two specimens (Mus. lve,ii'. ^o. 4797) were receiv«Ml. No sjx'i'ies very 

 closely related to this shell is at i)resent known from the dapanese 

 fauna, but there are a niunber of them in the Australasian seas. The 

 jjenus is perhaps represented l)y />. pcrplcvti Pilsbry, of Japan. I have 

 referred the Ibssil to nHoiiut rather than (.tihhiild, chielly on ac<'ount of 

 the sculpture and sciiiit pearly layer, but on such occasi(»us it is im- 

 ])racticablc to dettM-mine positively the precise relations. 



( ; I ; N KU A 1 . ( "< >N( ' LUSl ONS. 



Tin' e\ idence allorded by these tbssils indicates unmistakably that 

 tlu' fauna includin.u" them must have llourished in waters at least as 

 warm as tlio.se which at i)resent occupy the .Ta]>aii Sea, at a distance of 

 more than a t]n)usand miles to the southward. The oyster and Siph- 

 anuria show that the fauna was litoral and not an ollslioro or ileep- 



