1928 SYSTEMATIC 13 



the jugate character of ribbing, but has its ribs flexed on the lateral 

 area, ornament more delicate, shape more platycone. On superficial 

 view is very like Reynesella (Mon. I.O. Amm., Suppl. PI. xvn), but has 

 a hollow (septate) carina, different ribbing, and flat inner margin : in 

 Reynesella the inner margin is concave, there are distinct primary ribs 

 which branch — the ordinary Ludwigoid pattern ; in Zugella there arc 

 no primary ribs : there are only small swellings on the edge of the inner 

 area. 



Possibty the similarity of Zugella to Reynesella-like forms may have 

 partly contributed to the dating of its bed as hemera discites (Q.J.G.S. 

 xlix, 1893, 498, 499, § xiv, 8). The affinities of Zugella suggest a later 

 date than discites : possibly the bed was formed by deposition during 

 two dates. 



Nannina, S.B., 1927, T.A. vii, PL DCCLII. Genotype, N. evoluta* 

 S.B. ; a stouter species, N. undifera, S.B., DCCLIII. Differs from 

 Nannoceras (CDXLV) by its more developed suture-line and by ribs 

 connate (jugate) on the edge of the inner area — a small coronate stage 

 in preceding inner whorls. Distinguished from Sonninites alsaticus bj r 

 lacking the large septate carina and by its ornament being less pro- 

 nounced. This genus is presumably a phaulomorph series allied to- 

 Sonninites alsaticus, just as Nannoceras is a phaulomorph series of 

 Euhoploceras. Nannina is several hemerae later than Nannoceras : 

 the matrix of its two species indicates that they are from the same- 

 quarry and the same bed as the examples of Sonninites alsaticus. 



Maconiceras, S. Buckman, 1926, T.A., vi, DCLXXXIV ; Geno- 

 type, M. vigoense, S.B. A series of small forms (phaulomorphs ?) with 

 sigmoidal, bifurcate, fairly strong ribs well projected on the carinati- 

 bisulcate venter, and having a specially long ventral lappet. There is 

 much resemblance to the costate stage of Harpoceras falciferum, 

 J. Sowerby sp., but the ribs are broader and less falcate, and the 

 suture line is extremely simple ; one may suspect, however, that 

 specimens of this genus have not infrequently been quoted as Ammonites 

 falcifer. 



The name is taken from Macon, (Saone-et- Loire, France : Lissajous 

 named the first species in his paper, ' Toarcien des Environs de Macon, 

 1906/ There are now three species figured and named in Type 

 Ammonites : — 



1. Maconiceras vigoense t S.B., DCLXXXIV, (Vigo Brickyard, 

 Northampton), more umbilicate and sulcate than Grammoceras solonia- 

 cense, Lissajous, PL I, fig. 5. 



2. M. soloniacense, Lissajous sp., I, 5, lectotype, " de Soloniacum > 

 Soligny ; localite ou l'espece est assez abondante " (Lissajous, p. 28,. 

 note) ; = T.A. vii, DCCXXI. 



3. M. lassum, S.B., Id. DCCXXII - G. soloniacense, Lissajous,. 

 I, 4, in which there is considerable falling off in the strength of the ribs — 

 most noticeable in regard to the primaries. 



Mr. B. Thompson, F.G.S., informs me that the species of the genus 

 occur in the Cerithium Beds of the Upper Lias which overlie the strata 

 of the braunianum zone : so the hemeral term vigoense denotes a later 

 date than braunianum. 



Phaularpites, S. Buckman, 1928, T.A., vii, PL DCCLXXVa. 

 P. exiguus, Genotype and Holotype ; PL DCCLXXVb, paratype. This 

 Upper-Lias genus shows definite excentrumbilication which, reducing 

 the whorl-height, is balanced by a small increase of whorl-thickness, 

 instead of the usual gradual decrease. The ribs are somewhat between 

 falciform and sigmoid, numerous, small, fairly approximate, furcate or 



