respect* present! tin- characters of Periaphinctei ; tin-n t thi> 



<pp. ;, n .| 0rotamUf, Opp.. from lnli:i. are 

 allied, (In- last of u hie 1 1 i> aUo found in St ramberg M tin- oldest 



representative of its genus in Kun>pe; .-md this form -tan" 



n,. -ii- M, . ,/.,-'/. //'////'.< that il wa- at lir-t dhvetlv identified with 

 it b\ I'idet. Tin- form- allied then to <>/<-. //.<//V/-/'/////s, I'mm 

 the Knropean .\ro->iiii:Mi. Mi'i- 1> In- |l:ic-<| hd'c. 



To '' - nKtirriiiniift. the _irr>Mp Ulr. h/iltr/iu/nm .-. Lcyin. i> 

 vcrv lu-arlv ri'latc*!. wliicli, liowexci 1 . <|ocs not ->rcm in ha\r rniur 

 to us t'n.in India, l>ut from tlu- Ix.rcal i'f-i"ns. where Olc. di{>t'j- 

 < /;'/.< Kr\-., ami /io///y// i //r////x. Kr\>., IVoin Pcl^chora . tnnn tin- 

 >tartini: point. Tin- close allinity between the Indian and 

 Kn>-ian cephaloixxlons fauna- is well known, and apparently the 

 -n.up of Olr. liiilir/nifnniHx t'oniis a boreal series parallel with 

 that <!' the I ndo-.Me(literranean of Ol.r. tixtierianus ; the appear 

 anee of the tii'st uTouj) in Europe took place decidedly earlier 

 than that of the latter, and indeed synchronously with that of 

 the . \nialtha-a and Px-Ii-iimit es of the group Bel. subquadratus. 

 The duration of Olcottephanux in Ktiropc is very short, they do 

 not seem to extend beyond the Neocoraian, whilst they persist 

 in India for a long time in the form of flat types with wide 

 umbilicus. 



The character of Olcostephanus in contrast with Perisphinctes, 

 consists in a shorter l.od\ -chamber, embracing only about two- 

 thirds of ;( whorl, with a simpler aperture, bordered with a 

 Miiooth margin ; ilu- presence of ears has been observed only in 

 Oli-. ('iniflrt/i. which stands on the limits of both the above 

 era. Constrictions directed forward in the group Olc. a.s- 

 fterianws, \ci-y struno-. wantini:- as a rule, in that of Olc. l>i<li<-h<>- 

 tomut. Lobnhir line, as a rule, consisting of a siphonal, two 

 lateral, and three auxiliary lobes, the last of which sometimes 

 are s,,ine\\ hat dependent. Kxtcrnal side wit hont keel or furrow, 

 <mly in a very feu are the ribs there interrupted. 



Thirty-three -pe.-ie^. 



OLOOBTBPHANUS BHAWANI, StoL T. Ill, figs. 658, 659. 



(inu< SCAPHITES, Parkinson. 



The ,s'v/y;/j //.> . with the exclusion of Sr. Y'-(iini, form a very 

 good natural uroiip. very distinctly characterized by the involute 



