OHDKR II 



AMMONOIDKA 



VII. Mom-IKx KKATIDA. 



Some families reseml>l, l>n<-t<ili<>i<l,i ,i,nl 1m r, *//// 11r yottM . 



distinction being the presence of n .<//w// :.<,< <tl<n<>\ ///- ,,\,<li,\ y,/,, .,/ //.. 



< it li< i families very like (Josmoceratidae, but '//// coronal* iinn,,,/ ,!,<' /.///<// 



coronate adult* n/,/,,,/;- (,, /,/,,, ///,/// /// ////.< sm'es. 



Family 18. Morphoceratidae. (}lo))ose ami n.-nally involute forms with 



open umbilici showing young to be liighly coronate until a late -tage. Cottae "ii um- 

 bilical /ones single and wideh 



separated, but divide into verv 



broad bundles of line, do>ely- 



set ventro-lateral costae differ- 

 ing from those of all other 



groups exec] it some /'.//- 



*lihiiu-H,l,n>. Only one line 



of tubercles or nodes, wliii'li 



usually occur at umbilical 



shoulders. Kxternal and 



dorsal sutures resemble those 



of Periaphinctidae, but not so 



uniformly inclined apicad. 



In discoidal coronate shells 



the lobes and saddles are of 



equal length, and dorsum has 



two pairs of zygous lobes and 



two pairs of saddles. 



Morphoceras, Douv. ; 



Garantiana, Siemirad. ; Olco- 



stephanus (Holcostephanus auct.), Neum. ; Potyptychites, Simbirskites, Avt'i'ritt, I'/'n/iififx, 



Pavl. and Lampl. Upper Jura and 

 Cretaceous. 



Family 19. Beineckidae. 

 Discoidal shells with costae single on 

 the lateral /ones but bifurcated on 

 their outer parts, and with one or 

 two lines of tubercles, the first 

 near the point of 

 bifurcation of the 

 co>tae, and the 

 other near their 

 ventral termini. 

 Division of costae 

 lakes place along 

 ventro -lat era 1 

 angles and not on 

 or m-ar the um- 



KeiMckia Bt 



Fio. 1219. 

 Caracoles, Bolivia (alUT Sb-iniiianii). 





[nferlor Oolite ; Bayeox, 



bilical shoulders. 

 ('o>iae cross the 



\cnteronlyinthe 



in CoeloorK*. 



Fl... lL-.'l. 



! llaan sp. ('allovian; 

 *' (after 



coronate young, when >ed ion is trajnvoidal as 

 Sutures as in preceding family. 



Reineckia (Fig. 1219), Parkinsonia (Fig. 1220), Bayle ; Oeco/////rA //<.-, Xeum. (Fig. 

 1'221); Aulacostephanus, Sutner and Pomp.; (?) iramjenia, Neum., >''/- 

 nov. Type S. (Amm.) niortense, d'Orb. sp. Middle and Upper .lura. 



