464 Notices of Memoirs — Dr. E. Ton ITojsisovics — 



portion, may be considered as a connecting form between Ceratites 

 and Tirolites. The genus Ceratites, as adopted here, nearly coincides 

 with the group Nodosi, Beyrich. The convex portion is constantly 

 without sculptures, smooth, convex or flattened (in one series of forms 

 with an indistinct medial carina). The sides are covered with 

 moderately curved ribs or folds, multiplied by bifurcations or inter- 

 calations, and frequently adorned by umbilical, medial, and marginal 

 spines or teeth. The number of knotted spirals varies between 

 and 3. The anti-siphonal lobe is double-pointed. The Ceratites 

 of the German Muschelkalk are strikingly discrepant from the 

 Mediterranean types by the shallowness of their lobes, possibly in 

 consequence of anomalous proportions of the salt held in solution 

 by the old German Sea, in which the Muschelkalk was deposited. 



In Cerat. Khanikoffi, Opp., an Indian species, the notch of the 

 lobe-line extends over the tops of the saddles. 



Balatonites, Mojs. — This genus comprises the series of forms of 

 Balat. Balatonicus, Moys., Balat. eiiryomphahis, Ben., and Balat. Bra-- 

 gensis, together with the Central-European form Balat. Ottonis, Bucli. 

 Lobes like those of Ceratites; anti-siphonal lobe unknown. Convex 

 portion with a range of knobs running over its centre, in some cases 

 taking the form of a carina by confluence of the knobs. Bibs 

 numerous, constantly with umbilical and marginal spines, frequently 

 with one or more intermediate ranges of knobs. One form from the 

 Muschelkalk has on each side seven ranges of knobs, besides the 

 row on the convex portion. 



Acroclwrdites, Hyatt. — Only one very rare Mediterranean form 

 from the Upper Muschelkalk is connected with Acroch. Eyatti, Meek, 

 the American type of this genus, characterized by ribs, passing over 

 the convex portion, and alternatingly confluent by three and three 

 into a large knob on the umbilical margin, and other ribs, simply 

 terminating at the same marginal lobes as those of Ceratites. Certain 

 Mediterranean forms with continuous sculptures over the whole con- 

 vex portion, without any knobs, or with a number of small spirals of 

 knobs, may be conveniently ranked among this genus, which seems 

 to be very closely allied to Balatonites. Possibly Ammonites 

 spinesr.ens, Hauer, may find its place in it. 



Hungarites, Moys. — Narrow, fold-like ribs, high median carina ; 

 lobes like those of Ceratites. Possibly Ammonites scapliitiformis, 

 Hauer, so similar to Cerat. tropitus, a Permian form from the Araxes 

 defile, may rank in this genus. If there be a real connexion between 

 the Alpine Triassic forms and the Permian species from Armenia, it 

 would be a proof of genetic difference between the preceding and 

 the coeval European forms. 



Arpadites, Moys. — A limited, well-characterized group, represented 

 in the Mediterranean province hj Arp. Arpadis, Mojs., Arp. Szaboei, 

 Boeckh, Arp. Manzonii, Ben., Arp. Achelous, Mstr., Arp. brevi-costa- 

 tus, Klpst., Arp. sulcifer, Mstr., Arp. Rueppeli, Klpst., Arp. Sesostris, 

 Laube, Arp. Hirschi, Laube, and several new forms; — in the Juvavian 

 province by the groups of Arp. Hcernesi, Hauer, and Arp. Lanbei, 

 Mojs. (Arp. Bueppeli, Hauer). The genus is characterized by a deep 



