IN THE ANGLO-PARIS BASIN 149 



VII. REVIEW OF THE AMMONITE FAUNA 



The foregoing stratigraphical account has drawn heavily upon the evidence of 

 relative ages provided by the ammonites. For the purpose of this Bulletin the 

 subzonal distribution of the ammonite fauna of the Middle Albian, will be considered 

 only. Of the other stratigraphically useful fossils, some have been mentioned in the 

 text, but the foraminifera and ostracods require careful revision based on accurate 

 collecting. The two plates of zonal ammonites should be used in conjunction with 

 Spath's Monograph (1923-43). 



A. Description of new species 



In order to stabilize the new taxa used in this Bulletin, brief descriptions are given 

 of one species of Hoplites (H.) and two species of Anahoplites. 



Family HOPLITIDAE Douville 1890 

 Subfamily HOPLITINAE Douville 1890 

 Genus HOPLITES Neumayr 1875 

 Subgenus HOPLITES Neumayr 1875 



Hoplites (Hoplites) maritimus sp. nov. 



(PI. 1, figs. 3 a, b) 



1925a Hoplites rudis Parona & Bonarelli (pars) ; Spath : 108, pi. 8, fig. 10c, d. 



Derivation of name. Hoplites : — heavily armoured soldier, maritimus : — of the 

 sea. 



Diagnosis. Hoplites {Hoplites) with stout well-rounded whorl section bearing 

 coarse projecting tuberculate bullae about 10 per whorl, each buttressed by short 

 umbilical rib stemming from umbilical suture. Each bulla gives rise to two short 

 coarse ribs terminating above ventrolateral margin in coarse projecting clavi arranged 

 en-echelon each side of venter : intercostal areas merging onto venter. Ribs simple to 

 about 40 mm. diameter, thereafter there is tendency to develop occasional lautiform 

 ribs. Above 100 mm. ornament decreases in strength. Septal suture similar to 

 H. (H.) dentatus. 



Type material. Holotype BMNH. C 862a (J. S. Gardner Coll.) from Bed I (v) at 

 Folkestone. 



Dimensions. 53 -42 '$2 -32. 



Remarks. Like all species of this genus, H. (H.) maritimus shows variation 

 among individuals. Specimens of this form are, however, common in the lower part 

 of the spathi Subzone taking descent from the lyelli Subzone H. (H.) of the baylei- 

 benettianus group. At the base of the Subzone the ribbing is usually simple, but 

 higher up occasional intercalated ribs occur which produce a lautiform effect. Later 

 still, lautiform ribbing becomes well developed producing direct transitions to H. (H.) 

 canavarii Parona & Bonarelli of the upper part of the spathi Subzone. 



