'244: MESSES. G. W. LAMPLX7GH AND J. F. WALKER ON [May I903, 



ornamented and excellently preserved, but difficult to extract or 

 clear from the matrix ; the prettily-decorated mytiloid shell, 

 Septifer lineatus, is also abundant in some of the lenticles, with its 

 delicate markings intact. Large serrated spines of echinoderms 

 occur scattered rather plentifully in most of the blocks, their 

 characteristic oblique fracture being often visible on broken faces of 

 the stone, although specimens could rarely be extracted in good 

 condition ; a few tests of echinoderms were also obtained, all 

 referable to forms known in the Upper Greensand. Several frag- 

 ments of carapaces of a crustacean were found, and have been 

 identified as belonging to the genus Plagiophtlialmus. Joints of a 

 large round-stemmed crinoid, recalling the large Bourgueticrinus of 

 the Red Chalk, were rather numerous in two or three of the 

 blocks. Serpulce, probably of two or three species ; Aviculaz, not 

 well preserved ; a globose Lima ; and some small irregular oysters ; 

 are present in most of the lenticles. Polyzoa, encrusting other 

 fossils, are plentiful, but have not yet been worked out ; ramose 

 sponge-like bodies are also abundant, but sponges of the kind so 

 plentiful at Faringdon and at Upware have not been found. Of the 

 gasteropods which we obtained, some were in the condition of casts 

 and none have as yet been specifically determined. A single fish- 

 tooth, representing a species of Scapcmorliynclms, is the only 

 trace of vertebrate life that the bed has yielded to us. 



Among the rarer fossils, the most important is the cast of portion 

 of an ammonite in hard limestone, which led to close search being- 

 made for further examples, but without result. Although this 

 specimen is scarcely adequate for specific identification, it shows 

 sufficient of the shape and ornamentation of the original shell to prove 

 that the species cannot be Ammonites ( Acanilioceras) mammillatus, 

 and also that it is unlikely to belong to any of the commoner Gault 

 forms. It compares best with an ammonite collected by one of us 

 from the Hythe Beds at Hythe, which is believed to be Amm. 

 (Acanilioceras) Milletianus} 



The only other trace of Ammonites that we found was a small 

 smooth-worn fragment of a whorl in the condition of an ironstone- 

 pebble, which was of similar aspect to the fragments so abundant at 

 Potton and other places. 



Two fragmentary specimens of small Belemnites, probably im- 

 mature, were recently obtained from the quarrymen. One specimen 

 is still embedded in its matrix of gritty limestone, and the other 

 has a little of the same material still adherent to it ; so that there 

 can be no doubt of their occurrence in the band. Neither, however, 

 is sufficiently perfect for identification ; but they bear no resemblance 

 to the species occurring at Faringdon {Belemnites speetonensis, Pav.), 2 

 nor to any of the allied forms occurring in the ' Zone of B. bruns- 

 vicensis ' of Speeton ; they compare more closely with B. minimus, 

 var. attenuatus of the Red Chalk and Gault, or with a small 



1 ' Summary of Progress for 1897 ' Mem. Geol. Surv. p. 129. 



2 Geol. Mag. 1903, p. 32. 



