M. M. Brydone — Further Notes on the Trimmingham Chalk. 129 



8. difformis, so I gave this name to Dr. Rowe, but with the same 

 caution with which, it will be seen, I recorded it at Trimmingham in 

 my pi-evious pamphlet. Whether it ought to be included in the 

 same species as the typical S. macropus on account of its initial stage 

 is a question for a specialist, but it seems to me very undesirable, 

 seeing how greatly the two forms differ in the adult stage. (The 

 question is further complicated by a Trimmingham species, which 

 generally begins with a macropus stage like the form just described, 

 and then grows to a great length as a free round tube slightly 

 curved, with a carious surface and devoid of carinse. The same 

 form is, however, often to be found in the same beds free from its 

 earliest infancy.) S. canteriata, the third species, is evidently 

 the Trimmingham form which Dr. Eowe had in mind, as it is 

 the only free pentagonal species at Trimmingham (except 

 occasional specimens of S.fluctuata). Not content with gratuitously 

 attributing to me an intention to identify his specimen 

 of a heptagonal form with S. canteriata, which is never even 

 hexagonal, he has made misstatements about that species from 

 which a wider experience would have saved him. If he had said it 

 ■was always pentagonal outside the Trimmingham Chalk he might 

 well have been correct, as I have found only the pentagonal form in 

 the various zones down to M. cor-testudinariiim, in which it 

 occasionally appears, but in the Trimmingham Chalk it is often 

 tetragonal, and in some specimens passes from the one form to the 

 other. 



Dr. Rowe may be right in saying that Pentacrinus Agassizi and 

 Bronni are very common at Norwich and Sheringham, but I confess 

 I am much surprised at the statement, for I have not found a specimen 

 of either form at either locality, and I have spent much time on 

 the chalk around Sheringham, though comparatively little on that 

 around Norwich. 



B. Chalk between Cromer and Weybourne. 



Spongida. 

 Forosphcera glohularis, Phill. (very Ventriculites impressus, T. Smith, 



large) . V. radiatus, T. Smith. 



ACTINOZOA. 



Axogaster cretacea, Lonsd. Trochosmilia [laxa ?). 



Steplianophyllia Michelini, Lonsd. 

 (common). 



ECHINODERMATA. 



Bourgudicrinus (joints, including one Eehinocomis vulgaris, Eom. 



variety very tj'pical at Trimmingham). Echinocorys vulgaris, Breyn. 



Cardiaster sp. Goniaster (ossicles). 



Cidaris. Micraster cor-anguinum, Klein 

 Cyphosoma [Konigi?]. (common). 



Vermes. 

 Serpula amimllncea. Sow. Serpula granulata, Sow. 



S. canteriata. Hag. S. gordialis, Schloth. 



S. carinella (?), Sow. S. lituitis, Defr. 



S. difformis (h), Dix. S.pilexus, Sow. 



S.fluctuata, S. "Woodw. 



DECADE V. — VOL. III. — NO. III. 9 



