70 ALBIAN FOSSILS DISCOVERED AT OKEFORD FITZPAINE. 



The present specimens agree in every detail with d'Orbigny's 

 illustration on PI. 73 of his work quoted in synonomy, and with 

 an excellently preserved example in the British Museum from 

 Escragnolles, France. 



KANGE OF SPECIES. Restricted to the basal zone of the Albian. 



LOCALITIES. Sandgate, Folkestone, Ciockerton, &c. ; and from 

 several places in France, Switzerland, &c. 



HOPLITES BENETTIANUS, J. de C. Sowerby. 

 PI. ii, fig. 1. 



Ammonites JBenettianus, J. de C. Sowerby : Mineral Conchology, 

 1829, Vol. 6, PI. 539, p. 77. 



Ammonites interruptus, Orbigny : Paleontologie Franjaise, 

 Terrains Cretaces, Cephalopodes, 1840. PI. 31, p. 218. 



Hoplites Benettianus, Neumayr : Sitzb. K, Ak. Wiss. Wien, 

 1875, Vol. 71, part i., p. 684 



Two portions of this Ammonite are in the collection, that 

 selected for figuring being a cast belonging to as large an example 

 as is shown on d'Orbigny's Plate 31 (reduced one half), which has 

 a diameter of about 180 millimetres. In section it may be 

 described as semi-globose, or wilh sides rather compressed. The 

 peripheral region exhibits the characteristic alternation of the ribs 

 divided by a centrally smooth area, whilst the lateral aspect shows 

 long primary ribs, which are sometimes interrupted by an obtuse 

 tubercle before reaching the umbilical margin. From near this 

 tubercle proceeds a secondary rib, which, though free, curves so 

 closely to the others at its end as to give the appearance of 

 bifurcation. The ribs are robust, elevated, hook shaped at the 

 periphery, and somewhat curved on the lateral surface, where they 

 form boundaries to deeply sculptured grooves or channels. 



Many authors regard this species as a synonym of Hoplites 

 interruptus, but there is good reason for keeping it distinct. In 

 H. Benettianus we have an altogether coarser shell, more inflated 

 and much larger, besides being limited in its horizon to this 

 particular zone. 



