OBDBBD .\MM<N()IDKA 551 



Sub Order D. EURYCAMPYLI. Hyatt. 



Conchs fiinjinii in jn-imH.ii;- </.//</ ///// /V///.s like Anarcestes to hii/kln coronate 

 n-ith < at ire lobes and saddles. TJie ventral and lateral lobes become divided in specialised 

 Palaeozoic genera, and the more highly specialised Permian and Triassic forms have the 

 lobes and saddles complete!;/ <lir, '<!,</. Thf l<ir</r, inner saddles chara<< 'he ephebic 



stage of Magnosellaridae are retained throughout life in many Palaeozoic forms, and 

 occur more or less in the young of Triassic genera. Among tl' imt.r th> <"/<////. form, 

 of Gastrioceras is also common. 



\. MAGNOSELLAKIHA. 



Prevailing form of <-<>n>-li Annrcestes-like, but sometiii"-* <//><, ,/',/<//, //</ ///-/- ,,r less 

 quadrangular or tmji, :.,,!,!, il in section. Sutures entire, with large inner lateral saddles 

 resembling those of Glyphioceras in most Palaeozoic forms, but the lobes become more 

 digitated in some Carboniferous and Permian genera, and both lobes and saddles are 

 completely divided in highly specialised Triassic genera. Ventral lobe undivided in 

 primitive forms, but split by a siphonal saddle which i* in turn .^nh/lirided by in* 

 funnel lobes in the more specialised species. Siphuncle without calcareous sheath ; funnels 

 monochoantiic in primitive forms, and diplochoanitic or sometimes even cMoiochoanii 

 specialised Permian forms. 



Primitive genera have deep undivided antisiphonal lobes and only one pair of 

 large broad dorsal saddles ; the first pair of lobes, when present, are confluent with 

 the second lateral lobes at the lines of involution. More specialised shells may retain 

 a pointed undivided antisiphonal, but the dorsals may have one pair of entire narrow 

 saddles, one pair of entire pointed lobes, and usually a second pair of saddles. These 

 last are broad, similar to the lateral pair, or confluent with the third laterals when 

 there is a third external pair. 



Family 1. Magnosellaridae. Beyrich. Ammoniticones varying from discoidal 

 and Anarcestes-like to highly involute, 

 compressed shells with narrow venter-. 

 Septa concave along the mesal plane as 

 in Nautiloids, becoming convex only 

 internally and laterally, following tin- 

 broad internal saddles in the zone of 

 involution. Lobes and saddles entire. 

 Primitive forms may have only two 

 broad saddles on either side, but more 

 specialised shells may have two pairs <(' i,- 1(; . n L v,. I'M,. n-_>7. 



principal saddles formed by division of yv/ioeerasj*<rorw,v. Bucii. 

 the primitive first laterals.' There is a Jjfgg; rl } on " iln> B&hF^i^ 



corresponding development of narrow 



saddles and lobes on the dorsnm, but primitive forms have only two broad saddles 



here as in Anarcest'*. Anti- 

 siphonal lobe narrow, entire, 

 ~"V \/Y\/\/^V pointed. Aperture with hypo- 



nomic sinus. Shells smooth. 

 F " : - n - 8 - Fli; - n29 - Parodoceras (Cheilor.rat, 



Suture -line of >>>!/./.,<. .".. Sutiir'-line of Maeneceras tcre- u i\ / i i .> 



Afuiuteri, v. Buch. sp. bntel, Samlk s].. ^> 



1127). 8poradocenM{Fi& 1128), 



Maeneceras, Hyatt (Fig. 1129); rarntn, -noceras, gen. nov. Type P. (Gon.) l> ntifnrrnc, 

 Kayser sp. Gonioloboceras, gen. nov. Type G. (Gon.) goniolobn^ Meek >j. /'.- n>l>- 

 clymenia, Freeh. Devonian and ( 'arboniferous. 



Family 2. Pericyclidae. Involute shells resembling Glyphioceratidn,; but having 



