630 



MOLLUSCA 



PHYLUM VI 



Meek (Äphißlites Mojs.) (Fig. 1173); Palaeogoniatites Hyatt. Type 

 P. (Goniatites) lituum (Barrande). Devonian. 



Paraphyllites Hyatt. Type P. {Goniatites) tahuloides (Barr.). Dorsiim of this 

 involute form is entirely occupied by a large azygous lobe terminating in a minute 

 annular lobe and partial cone similar to that observed in Nautiloids and in Pinacites. 

 The inner extension or cone is not present elsewhere among Ammonoids so far as 

 known. Devonian. 



Pinacites Mojs. Highly involute, compressed ammoniticones with acute venters. 

 Septa biconcave, owing to a division of the lateral lobes by narrow saddles which 

 are connected by ridges with corresponding saddles on the dorsum. There are also 

 saddles at the unibilical angles and on either side of the ventral 

 lobes. The azygous dorsal lobe is large. Dorsum vi^ith one pair 

 of narrow zygous saddles and one pair of broad zygous lobes, 

 giving a formula of eight lobes and eight saddles. European 

 Devonian. 



Family 4. Tornoceratidae Gürich. 



Involute forms, luith ventral sinus, simple septa lihe those of 

 Fig. 1174, ^^^ AphylUtidae, and relatively short hody-chamhers. 



Tornoceras simpiex (v. Tomoceras Hyatt (Fig. 1174), Maeneceras Hyatt (Fig. 1176). 



Buch). Upper Devonian; t^ • J \ ö /» j \ b j 



Büdesheim, Eifel. Devonian. , 



Family 5. Cheiloceratidae Frech. 

 Ammoniticones varying from discoidal and Änarcestes-like to highly involute, com- 



'a^wvv^' 



Fig. 1175. 



Suture-line of Sporadoceras 

 münsteri (v. Buch). 



Fig. 1176. 



Suture-line of Maeneceras 

 terebratus (Sandb.). 



Fig. 1177. 



Suture - line of Aganides 

 sulcatus (Münster). Upper 

 Devonian ; Fichtelgebirge. 



Fig. 1178. 



Aganides rotatorius (de Koninck). Lower Carboniferous ; 

 Tournay, Belgium. 



pressed shells with narrow venters. Shells smooth, hut with frequent labial constrictions. 

 Body chamler long. Aperture without hyponomic sinus. 



In this family the septa are concave along the mesal plane as in Nantiloids, 

 becoming convex only internally and laterally, following the broad internal saddles in 

 the zone of Involution. Lobes and saddles entire. Primitive forms may have only 



