104 mr. s. s. btjckman on [June 1913, 



obviously refers to a Peltoceras. I have received from the Whitby 

 Museum a specimen supposed to be the type. It is rather more 

 than 2 inches in diameter, and is then three-quarters of an inch 

 thick; but it does not altogether agree with the description. 

 Further search for any specimen so named by Simpson may be 

 requested of those who have charge of old collections of Scarborough 

 fossils. 



Peltoceras subtense. Leckenby identified this doubtfully with 

 Ammonites arduennensis d'Orbigny, but it is not that species. The 

 regular radial (versiradiate) costse, which bifurcate about the 

 middle of the lateral area, distinguish it from d'Orbigny's species. 

 The position of furcation distinguishes it from many other species. 

 It is a much compressed form, carrying the costate stage a long 

 time, and hardly attaining to the bituberculate stage. The largest 

 example is 176 mm. in diameter. 



Phltcticeras hyperbolicum. Simpson's Ammonites liyperoolicus 

 is a most remarkable and interesting species. It is the senile 

 development of the genus Phlycticeras, 1 which, so far as I recollect, 

 has not yet had any of its species recorded from England. It has 

 lost nearly all ornament, though there remain just sufficient traces 

 of rib-contour to indicate the generic association. The keel has 

 been reduced to a mere ridge. Such a senile species of the genus 

 has not, so far as I know, been recorded. 



Qtjenstedtoceras GREGARitiM. This species has as a distinctive 

 feature ribs much forwardly inclined across the whorl (prorsi- 

 radiation). A Prussian species, Amaltlieus leachi Nikitin 2 (non 

 Sowerby), has the same style of tangential ribbing — as if the 

 periphery had been turned forwards around the centre ; and it has 

 much the same proportions. Another Russian species, Amalthevs 

 rybinsleianus iNfikitin, 3 is what one would expect as the involute 

 stouter-whorled development. I have not seen such tangentlally 

 ribbed forms from any other English localities where other Quen- 

 stedtocerata abound. 



Quenstedtoceras xoNG^Evt/M. Leckenby's placing of this as a 

 synonym of Ammonites lamberti Sowerby was not correct. The 

 Bean types show two species belonging to two different stocks, 

 one is near to Q. placenta (see below) and the other belongs to 

 the Cadoceras-greivinglci series (see Cadoceras, sp. nov., p. 162). 



Quenstedtoceras marine. D'Orbigny ('Terr, jurassiques: Cepha- 

 lopodes ' pi. clxxix) has several forms under this name. It is 



1 Phlycticeras Hyatt = Lo2?hoccras Parona & Bonarelli. Tor a treatise on 

 the species see their work, 'Call. inf. Savoie' Mem. Acad. Savoie, ser. 4, 

 vol. vi (1895) p. 90. 



2 'Die Jm-a - Ablagerungen zwiscLen Kybinsk, &c.' Mem. Acad. Imp. 

 St. Petersb. ser. 7, vol. xxviii (1881) No. 5, pi. i, fig. 5. 



3 Id. pi. i, fig. 8. 



