PROLECANITES. 51 



Dimrnsioiin <;/ the tt/pe specimen. 



Millimeters. 



, Dianu'ter 27 



Height iif last wliorl H. 5 



Hfiglit 111' last wliiirl I'mm the preceding 9. 5 



Width of last whui-l 6 



Involution o 



Width of umbilicus, about 3 



The specimen was septate tlirovigliuut, and must, if comjilete, have 

 reached at least twice this size. 



Family PROLECANITID^ s. str. 



In this paper the superfaraily Prolecanitida? is used in the broad sense, 

 as it was by Karpinsky, and is thus equivalent to IlA'att's superfamily 

 Prolccanitida. The family name ProlecanitidaL^ is applied only to the 

 immediate allies of Prolecanites. E. Hauo" has recently proposed to sub- 

 stitute for this group the name Ibergiceratidte, based on a supposed genus 

 Ibergiceras Karpinsky, thought to represent the radicle of the stock, from 

 which Prolecanites, Paraprolecanites, and Pronorites came. But HolzapfeP 

 has shown that the genus Ibenjiceras, (Gon. fetrcujomis Roemer) was based 

 merely on a young specimen of Pronorites cyclolohns, and came, not from 

 the Devonian, but from the Lower Carboniferous limestone of the Iberg in 

 the Hartz. 



Genus Prolecanites Mojsisovics. 



The genus Prolecanites was named by Mojsisovics" to include evolute, 

 compressed forms, with wide umbilicus, slightly embracing whorls, and 

 goniatitic, lanceolate septa. The external lobe is undivided, the two or three 

 lateral lobes pointed and tongue-sha))ed. The saddles are spatulate and 

 rounded. The antisiphonal lobe is long and ])ointed, flanked l)y a pair of 

 short, rounded lobes. 



As restricted by Hang,'' Prolecanites is contined to the uppermost 

 Devonian and the ('arboniferous. The type of the genus is Goniatites 

 mixolobtis Sandbei'ger of the Lower Carboniferous. One American species is 

 found ill the Middle ( 'oal Measures. 



« Etudes sur les Goniatites, p. 50. 



'^Die Cephalopoden dei^ Domanik ini siidliehen Timan, ]>. 45. 



'Cephalop. der Mediterianen Triasprovinz, p. 199. 



f' Etudes sur les ( ioiiiatites, p. 52. 



