01 run KRAH, MJoi'i |)i 



:illl extendilli: aero the founded abdomen, a- ill /'/- 

 The Bepta are minutely divided ly minor loin--,. v.-i\ elofielj 

 Tin- abdominal lobe IB deep; side- .-il.nipt. Superior latrral \.T\ 

 ,'iarro\\. deeper tliiin the abdominal, and | irot'u-rl \ I r:i m-li i MU- 

 Inferior lateral not MS deep :i- -n | ierir lateral. :nnl o!' :ilioiit the 

 -aim- l>n-:i<ith mid L!cii-r:il .-ispcct. A li(loinin:il crll hir^r ;nid 

 M-rr.-iti'fl. Sii|-rior l:itrr:il \ir\ liro:il. :ilnm1 t he s;ini<- lici-jlit ;i- 

 ihc iutrrior I:i1cr:il. 



Mi.l'il, Lias. 

 \\ i, ATI COST \T \. S>\vl). T. los. Ho-. i;-ji;. 



CTOLOCERAS. AMoiiM-ii roumlcd or keeled. m>t -M lro;id afl 

 Ihc ilorxil si.h- of Ihe \vhorl. I'iln- siiin-|i. t ul)crciil:itcd. ;ind not 

 Cross the :ilMloiiH'ii ill tin- Ucch'd >|MMM-. ^'oiin-j 

 smooth t'r tin- lirsl two or three wliorls. then l>ecome rihled. 

 Keel :i|i|n-Mi^ at Mil eMrlier stM^'i- of growth tliMii the j)il;e. St-|1:i 

 not BO minutely divided ly minor lolies. and the hirii-er lobes les* 

 deiitritie tluin in /'/f/////</r///--f/v/s. The ;ibdoiniiiMl loin- of 

 im-iliiim depth Mild (piite 'hro.id. Superior hitem! of me<lium 

 hreMdth Mild considerMl>le depth. Inferior hitcrul :ibout two- 

 thirds MS hroMd Mini deep MS superior lateral. One small auxiliary 

 lole exposed laterally. Superior lateral cell broad and depressed. 

 Inferior lateral more prominent and mirro\ver; small auxiliary 

 cell exposed oil the side. 



Middle Lias. 

 C. V \u. AM. d'Orb. T. 110. li-s. r,4-J, 04. 



TKOI-I IHM-KHAS. Altdomen invariably keeled, much narrower 

 than the <lorsal side of the whorl. Pihe siuole, smooth ortuber- 

 eulate<l in the -Mine species, do not extend Mcros> the abdomen in 

 any species. Yonnu; an- .-month for one or two wliorls. Keel 

 and pil;e appear simultaiieou-ly. Septa have a more complicated 

 M-pect than in the precedino ^i-nus, the minor lobes beinii deeper 

 and more numerous. 'The abdominal very broad at the bottom, 

 narrower above. Superior lateral lobe narrow, ami about the 

 xime depth as the abdominal. Inferior nearly the -ame. but le-> 

 brMnchiiiu" than the -uperior latei'al One auxiliary lobe cx|M<ed 

 on the >ide. Abdominal cell very broad. Superior ami inferior 

 lateral cells very irregularly divi<le(| by minor loin--. One small 

 auxiliary lobe exposed on the side. 



Mtik 



f ri:..|'il)orKi{ \s A- T io\. d'< >rb. 'I'. 108, figB. 697, 628, 

 80 



