G82 



MOLLUSCA— CEPHALOPODA 



PHYLUM VI 



the uppermost Cretaceous ; maximum from the Middle Lias to Lower Cretaceous. 



Distribution world-wide ; most abundant in Europe, Asia and North America. As 



an index fossil of the Jura 

 and Cretaceous, this genus 

 is scarcely less important 

 than the Ammonites. 



Subtfenera : I'achytcufJiis 

 Bayle (Fig. 1318, A).' Guard 

 perfectly smooth. Contined 

 to the Lower Lias. £. acutus 

 Mill. 



Mcgateuthis Bayle , {Dac- 

 U/loteuthis Bayle, Paxillosi) 

 (Fig. 1318, B). Apex of 

 the guard with two or three 



Fig. 1317. 



Belcmnites (Duvcdia) 

 dilaMtus' Blv. Neo- 

 comian ; Justithal, 

 Lake of Tliun, Switzer- 

 land. 



-I 



i::-J 



fe,--'JI 



Fig. 131S. 



-4, U. (Fachyteuthis) acutus Miller. Lower 

 Lias ; Lyme Regis, Dorsetshire. B, B. (Mega- 

 teuthi':) 2mxiUosus Schloth. Middle Lias ; Metzin- 

 gen, Wiirtemberg. (', B. (P^eudohdus) hijiariitiifi 

 Blv. Lower Cretaceous ; Castellaiie, Basses 

 Alpes. a, h, c, Dorsal and ventral aspects and 

 cross-section, i/j. /), B. {Brlcinnopsis) canalicu- 

 kit us Schloth. Inferior Oolite ; Wiirtemberg. 

 E, B. (Bdemno}isls) liastatus Blv. Oxfordian ; 

 Dives, Calvados. 



§M 



Fig. 1319. 



Belernnitcs {Actinocamax) quad- 

 ratus (Blv.). Upper Creta- 

 ceous ; Germany. -1, Dorsal 

 view of guard with deformed 

 phragmacone projecting from 

 alveolus. B, Ventral aspect of 

 guard. C, Alveolus from above 

 (after Schltlter). 



usually short grooves. Middle Lias to Lower Cretaceous. B. paxillosus and B. giganteus 

 Schloth. ; B. clongatns Mill. ; B. subquadratus Roem., etc. 



Belemnopsis Bayle (Hiholithcs Montf., Gastrocoeli, Canaliculati, Hastati) (Fig. 1318, D, E). 

 Guard with deep and usually long ventral furrow extending from alveolar margin toward the 

 apex, with or without dorso-lateral lines. Middle Jura to Middle Cretaceous. B. canaliculatus 

 Schloth. ; B. absoliitus Fisch. ; B. unicanalicu.lcdus Zeit. ; B. minimus Lister. 



Fscudohclus Montf. (Bijiartiti) (Fig. 1318, C). Guard thin, slender, with deep dorso- 

 lateral grooves, with or without ventral furrows. Upper Lias to Lower Cretaceous. B. cxilis 

 d'Orb. ; B. hipartitus Blainv. 



Adinocnmax l\Iiller [Goniotcuthis Bayle) (Fig. 1319). Guard cylindrical, subniucronate, 

 with short but very deep ventral furrow ; anterior end foliaceous, and very liable to dissolu- 



