AM.MONolDKA 



involute, but stout-whorled ami k--ile. , beooining more compressed, ami having a broad 



slightly elevated median ventral i-idge in more .-periali-.-d genera Side- liave at h-a-t 

 one line of nodes in primitive forms, and are more or le.-s completelv costated with 

 several lines of tubercles in specialised shells. Sutures in the young and in primitive 

 genera have a tnagnosellarian aspect, but when the broad 

 internal saddles become divided, the internal inllection- 

 resemble those of Lecanitidae. In primitive forms 

 (Olenikites) the saddles are broad and very -hallow ; lobes 

 entire, and ventral !<>be divided by a larvit'orm .-iphonal 

 saddle, which is sometimes entire. 



The large nodes and stout volutions of primitive forms 

 indicate parallelism with Sfi/,/m ////,.< and l' rn*i, II'IKI ,nt, * 

 of the preceding family. Saddles and lobes have tin- 

 typical ceratitic outline.-, as a rule, but in some forms 

 the auxiliary line may be extended as in Gyronitidae. 

 Occasionally, also, costae may cross the venter a- in 



Pa/raoen*UutoiodotiH t B 



* 



Ceratites, Haan (Fig. 1143); Danubitet, Mojs. ; Bala- 

 ionit es, Mojs. ; Retftingite8,Aiibsiber; Gymnotoceras, Hyatt ; 

 Paraceratites, gen. nov. Type P. (Cer.) elegans, Mojs. sp. 

 (Fig. 1144); Olenikites, gen. nov. Type 0. (Din.) spini- 

 plicatus, Mojs. sp. Keyserlinyites, gen. nov. Type K. 

 (Ger.) subrobustu*, Mojs. sp. ; Arctoccras, gen. nov. Type A. (Cer.) polari*, Mojs. ?-p. 



IV. TlROLITIDA. 



Primitive forms compressed, discoidal, and have only one pair of narron- >'iitir>' lateral 

 lobes, and tm> broad entire saddles with incomplete lobes in the umbilicus as in Parodo- 

 ceras. Number of inflections seldom exceeding three or four, 

 -and the ausilianj xntnr>'x never much extended. 



Family 12. Tirolitidae. M<.jsi>.ivi> y ">*). Com- 

 pressed, discoidal, or involute shells resembling J>iimn'fi(l<i-- 

 in their sutures, and having entire saddles and slightly 

 denticulated lobes. Ventral lobe may remain entire until 

 a late stage in some forms, but as a rule it is divided, and 

 siphonal saddle is small and often entire. Shells have a 

 line of nodes on the ventro-lateral angles, and the venter 

 is invariably smooth and convex. 



Includes T indites (Fig. 1145) and Metatirolites, Moj-.. 

 from the Alpine Trias. Sub -Family CLYDONITINA!:. 

 Suture.- similar to Tirolites, but costae interrupted on the 

 venter, which is often channeled. Includes {^yd,,,, //,.>- t 

 Eremites, Hauer ; and Ectolcites, Mojs. Tria-. 



Family 13. Dinaritidae. Mojsisovics (pars). 

 Sutures re.-eml.liiig Tinditi'x in having only two broad 

 .-addles, one pair of first lateral lobes, and incomplete lobes- 

 at the umbilicus. Shells smooth, or with coarse folds most 

 " prominent at the umbilical shoulders; sides more or leas 



flattened or plano-convex, and venter rounded. 

 Dinarites, Mojs. (?) Pseudoharpoceras, Waagen ; Pseudodiixiriii-*, gen. nov. Type 

 P. (Din.) mahommedanus, Mojs. sp. Trias. 



Family 14. Buchitidae. Primitive forms -imilar to Celtitidae, with smooth 

 elevated venter ; more specialised shells with slight keel on the narrow venter, and 

 simple costae or folds on the sides. Sutures have entire outlines, or lobes but slightly 



FIG. 1145. 

 Tirolites Cassianus, Quenst. sp. 



