28 



tnore tlajish, lioinj; iu>t Iw« tlmn 7.3 incU're. Uf this thickiiMW, 3 inetcn» beloof^ 

 to thf iipiKT diluvial loiiin (which itwlf ia covcro«! by 0.5 to 1.5 iiu'tcn* ot'aoill, 

 anil 4.:^ nu'tors to the dilTiTt-nt jmrts .if the lower liiliivial formation ('J.3 clay, 

 0.3 coiigl(iiiit'nit4f< ami 17 day a^aiii. inejisiirii«! from alifivc.) 



The »hell-lnyers arc foiiiul immediati-ly Wlow the line of nneonforniability 

 which i.-» siifliciontly iimlnlatinf^ to be njcognizi-d ; they slowly jnuw into itn|>iin^ 

 «lark clayish strata, soim-what jjoorcr in organic remains, ami in the lowivt |«rt 

 coiitiiining ainioft none at all. ThoiH' clays are visible in a thickness of 3 meters 

 mesifliired from the shell-layer, which, in the uverat;e, it« not thicker than 0.3 

 niettrrs, thoiijjh Rotnctimes rising to nearly 1 ni The dilTeretice it e.vhibit« from 

 the — unconlormable— diluvial depositc, is of course much shar{n;r, and aUive 

 all we do not find any well pr«««rved shells al)ove the line of [nrtitinn. There 

 are only a few uists, a|>|iarent1y lielonging to shells of the same s|icoie0 as thocu 

 of the layt^r. inilH-ddi-d in fhi-m together with fnignifiits of wikkI »-tc. The shell 

 layer is not confined to the mill, but extends to the north and went. Here it is 

 rei)eatedly intersected by cuttings made for canals, and sometime« also it appears 

 in the banks of the river itself. But it is not uniformly rich, as we may sod in 

 many of those place», some of which seem to have Iwen in .some instances mis- 

 taken for remains of shell-mounds- The true Rliell-muunds, alluded to by 

 Profcflsor Morsi' in his memoir, are, however, quite different and situated Imth 

 sides of the mad from Tokio to Oji, near this place, but next to a village named 

 Nishiga-Hara-Mura. At a larger distance from the mill, the numlier of nhells is 

 rapidly diK-reasing, at least as far as the investigation of the layer coulil U- car- 

 ried on ; and as all the 8|)ecie8 found in the other places are include<l within the 

 number of those toiuid next to the mill (in the steep slojic seen behind the mill 

 swni in the sketch, along the small canal, and in the tunnel to the right». I may 

 confine myself to the following list of sjttxie« foimd in this locality. 



THE .'^UKI.LS OF THK LAYKK AT OJI. 



GiisteropoJa. 



yepttiiieit arthtitira Valeiicii'Unes. i'late II lig. 1 (ciiin[>t<-s rr-udiis di- 

 I'aeAfl.iles sciences nat. 18jS, v..l.4ti, page 7G1. Ik-rnardi, Journal de Condi 

 vol. fi. Page. 386, plate 12, of 3. Sohrenck, Tritoniun» arthriticum. Nord- 

 jap. Moll, page 421. Lischke, Japanische Meeresconch. v. 1. jMge 37.) 



Not very frequent at Oji. Recent at Hakotiatc; as to the generic denomi- 

 nation, I think it \>e»X to adopt I>iven's genius. 

 Trophon Gunneri Loven. 

 (Index Moll. Scand. i>agc 12, No. 84. \Voo<l, Crag Mollusca, Siippl. |iage 

 27, t. 3, fig. 1«.) 



This spt'cii'«, recent from the Iwreal seas, fossil from the glacial UhIs and 

 according to S. V. W<kmI from the Norwich Crag of England, has ln-en very nirely 

 found at Oji. I have before me only I 8|iecimen with 5 whorls, 2 of which are 



