664 



MOLLUSCA 



PHYLUM VI 



1288) ; Ataxioceras Font.; Fro2)lanulites Teiss. ; Pictonia Bayle ; Crasj^ecUtes Pavl. and 

 Lampl. Inferior Oolite and Cretaceous. 



Fig. 1286. 



Suture line of Perisphinctes colubrinus 

 (Rein.). 



Fi(i. 12S7. 



Pcris'phincies polyplocus (Rein.). Upper 

 Jura ; Pappenlieim, Bavaria, i/o. 



Fio. 1-288. 



I'crisphinctcs tiziani (Oppel). Upper Jura (Biniamniatu.s Buds) ; 

 Hundsriick, near Streichen, Wiirtemberg. 



Subfamily E. Morphoceratinae Hyatt. 



Globose and usually involute forms with open umbilici showing the young to Ije 

 highly coronate until a late stage. Costae on umbilical zones single and widely 



separated, Init divided into 

 very broad bundles of fine, 

 closely - set, ventro - lateral 

 costae differing from those of 

 all other grouj^s except some 

 Perisphinctinae. Only one 

 line of tubercles or nodes, 

 which usually occur at um- 

 bilical shoulders. External 

 and dorsal sutures resemble 

 those of Perisphinctinae, but 

 not so uniformly inclined 

 apicad. In discoidal coronate 

 shells the lobes and saddles 

 are of equal length, and 

 dorsum has two pairs of 

 z3'gous lobes and two pairs of 

 saddles. 



Mori^hoceras Douv. ; 

 Garantiana Siemirad. ; Olco- 

 stephanus Neum. {Holcostephanus auct.) ; I'olyptychites, Simhimkites, Astieria, and 

 Virgatites Pavl. and Lampl. Upper Jura and Cretaceous. 



Fic. 128ii. 

 Reineckid hrancoia (Steiinn.). Caracole.s, Boliva (al'lcr Stciiimaiin). 



