96 MK. S. S. BTTCKMAN ON . [vol. lxxvi, 



by A. d'Orbigny. 1 This was rescued from a rockery at Headington, 

 near Oxford, and is from the well-known nodule-band. It would 

 have formed part of a specimen some 415 mm. (16 inches) in 

 diameter, and, allowing about another whorl for completion of 

 body-chamber, as one may with such forms, it must when alive 

 have been a giant exceeding 600 mm. (2 feet) in diameter — thus 

 rivalling the megalomorphs of the Portland Stone. And it was a 

 massive form, for the fragment gives 115 mm. (4| inches) of 

 whorl-breadth over its strong ribs. 2 Such giants seem to be a 

 new record for the Kimmeridge Series ; but the workmen at the 

 brickyard of Long Crendon (Buckinghamshire) had reported that 

 some years ago, in making an excavation deeper than usual — that 

 is, a few feet below Hartwell Clay — they had encountered speci- 

 mens as large as barrow-wheels, that would be in the position of 

 the same bed. Unfortunately, this brickyard is now closed and 

 dismantled. 



IV. Emendations and Corrections or the 

 Earlier Paper. 



Certain errors happen to have crept into my former paper, 3 

 partly misprints, partly misapprehension of information kindly 

 supplied. Some further information has also been published, and 

 other data have been communicated to me, in some cases suggesting 

 certain emendations. 



P. 259, line 10. For three read there. 



Table V, facing p. 267; Dorset Coast, Bed 103. For D[eruceras'] aff. 

 lorioli read Microderoceras aff. lorioli. 



The presumed generic position of this and allied species is 

 explained in the Pakeontological Appendix (pp. 306, 307), written 

 long after the table was prepared ; and the lapse of uniformity 

 escaped notice. Dr. W. D. Lang has now shown me, as the result 

 of further work, fragmentary crassicostate Bcliiocerata of rari- 

 costatoides pattern from the base of Bed 103. The association 

 with Microderoceras aft", lorioli j)oints presumably to non-sequence 

 and derivation as resiilt of erosion ; there is still no evidence and 

 no room for the aplanatum and macdonnellii faunas (Baasayan 

 6, 5) on the Dorset Coast. 



It may be suggested that it is advisable to separate for 

 recording purposes the lorioli fauna and horizon from those of 

 leckenbyi. The former occurs at Padstock, according to Mr. J. 

 W. Tutcher, in the ' base of armatus ' {leckenbyi, Paasayan 7), 

 which accords with the Dorset evidence : there it is found 

 distinctly below leckenbyi and allies. The following analysis 

 (Table XI) seems to indicate that there may be two horizons, 

 because the geographical ranges do not coincide. 



1 IV, 1, p. 558 & pi. ccxvi, figs. 4-5, pi. ccxxi (giganteus). 



2 Author's Coll. No. 2939. 3 II, 8. 



