Tpart 1] G4.ULT AND LOWER GKEEIS^SAND NEAR LEIGHTUN. 47 



■appear to belong to species previously unknown in this country. 

 The following notes are intended to give a general idea of the 

 ••additional fauna, without pretence to palaeontological accuracy, 

 except in the case of certain specimens at Cambridge, duly indi- 

 ^cated, which have been submitted to expert examination. 



Cephalopoda. — Although fossils of this Class have continued to be 

 exceedingly rare, a few specimens have been obtained which are of high 

 -import. It was mentioned in the previous paper that the cast of portion of 

 •an ammonite had been found, which, though not identifiable, showed affinity 

 to ' Ammonites milletianus.' The Walker (Cambridge) Collection now con- 

 tains four specimens, all showing the same general features, three of them 

 j)Oorly preserved, but one, the largest, a sharp ferruginous cast, | inch in 

 diameter, in good condition and showing traces of nacreous lustre, which has 

 .been identified by Dr. Kitchin as Leytneriella regularis (Bruguiere) ; and there 

 is little doubt that the ammonite mentioned in our first description was of 

 the same kinship. This species and its allies are the commonest forms in the 

 ..gritty phosphatic nodules of the Basement beds at the Chamberlain Barn and 

 Grovebury pits (pp. 30 & 36). Dr. Kitchin & Mr. Pringle speak of the lime- 

 stone-specimens as ' derived from the tardefurcata bed ' (K. P., p. 102), but 

 the state of the specimens runs counter to the hypothesis of derivation, 

 which will be shown also on other grounds to be improbable (p. 55). Their 

 •condition is quite diiferent from that of the small round waterworn fragment 

 of a whorl referred to in L. W., p. 244, and now in the Cambridge collection. 



Another species of ammonite yielded by the limestone is represented by a 

 .single specimen which, in 1920, rewarded my search in recently- excavated 

 material at Harris's pit. The shell, about an inch in diameter, is somewhat 

 -crushed, but otherwise fairly well-preserved, and is a smooth discoid form, 

 without ribs, agreeing well with the form common in the Mammillatus-beds, 

 ■which has been named provisionally ' Ammonites beudanti.' This form occurs, 

 along with ' Ammonites regularis,' in fair numbers in the gritty phosphatic 

 -nodules of the Grovebury and Chamberlain Barn pits, where they are associated 

 with scanty examples of ' Ammonites mammillatus ' (pp. 30 & 36). 



With regard to the belemnites, no additions have been made to the two 

 fragmentary specimens ijreviously recorded, of which one is now at Cambridge 

 ■and the other in my own collection. The form, as stated before, is near to 

 ' Belemnites minimus,' although rather larger than the average of that 

 ■species. I notice that a German investigator, in discussing recently the 

 -Lower Cretaceous sequence of North Germany, recognizes a form intermediate 

 between ' Belemnites aff. strombecki ' and ' B. minimus ' in the ' Zone of 

 -Hoplites regularis,' and proposes for it the name Neohibolites minor StoUey.^ 

 -It is likely that the Shenley belemnite belongs to this type. 



Gastropoda. — This Class is represented in the collection at Cambridge 

 by many unnamed specimens, mostly in poor condition, but a few probably 

 -identifiable. They include examples of ' Pleurotomaria,' and probably others, 

 in addition to the genera already recorded. I recently collected a good cast 

 •of ' Scalaria ' from the limestone. 



Lamellibranchiata. — Most of the species previously recorded are 

 -represented in the collection at Cambridge by a few additional specimens, 

 -alopg with which there are several species new to the list. Some have not 

 .yet been identified; but the following determinations have been made by 

 Mr. H. Woods : — Inoceramus concentricus Parkinson (3 specimens : the 

 -largest about ^ inch in length) ; Isoaixa obesa (d'Orbigny) (5 specimens, 



1 E. StoUey, ' Beitriige zur Kenntnis der Cephalopoden der Norddeutschen 

 TTnteren Kreide : 1. Die Belemniten des Norddeutschen Gaults (Aptien & 

 Albien)' Geol. & Palaeont. Abhandl. n.s. vol. x, pt. 3, 1911; also 'Die 

 'Gliederung der Norddeutschen Unteren Kreide ' Centralbl. fiir Min. 1908, 

 p. 246. 



