G. C. Crick — Note on Adiiiocamax, etc. 407 



appearance and composition throughout their length. The con- 

 stituent detritus at Ladock, Trevalsa, and Pentuan is as large as 

 peas or nuts." De la Beche also refers to these beds ^ flanked by 

 the slates of St. Stephens and Probus respectively north and south 

 of them. 



The main southern mass of these grits passes from Mevagissey, 

 Gorran, Caerhayes, Portholland, north of Portlooe and Carne to 

 Treworlas, from which point it has been traced and described by 

 iHill- as Porthscatho beds, south of Falmouth by Helford to Looe 

 Pool and Helston. 



The succeeding lower beds have been described by the same 

 author under the name of ' Veryan Beds,' and he includes in them 

 apparently the coarse conglomerates which I consider to be the base 

 of the Gedinnian and corresponding to the base of the Devonian 

 system on the Continent. 



The discovery of fossils of Ludlow age in the Caerhayes limestone, 

 referred to in the Geological Magazine for July, 1904, tends to 

 confirm this view. The unconformity of these conglomerates with 

 the underlying rocks would appear probable from the included 

 fragments of similar slates and quartzites. The junction of the 

 ■Gedinnian with the underl3'ing beds seems to be in many instances 

 accompanied by pillow-lavas, a note on which will be given by 

 Mr. Prior later on. 



V. — Note on Actinocamax, Miller ; its Identity with 



Atractilites, Link. 



£y G. C. Crick, Assoc. R.S.M., F.G.S., of the British Museum (Natural History). 



IN a paper entitled " Observations on Belemnites," which was 

 communicated to the Geological Society of London in April, 

 1823,^ J. S. Miller defined the genus Belemnites thus: — "A cepha- 

 lopodous ? molluscous animal provided with a fibrous spathose 

 conical shell, divided by transverse concave septa into separate 

 cells or chambers connected by a siphuncle ; and inserted into 

 a laminar, solid, fibrous, spathose, subconical or fusiform body 

 extending beyond it, and forming a protecting sheath." In May 

 of the same year Mr. Miller contributed to the same Society 

 another paper ^ in which he instituted the genus Actinocamax for 

 " spathose bodies which resemble the belemnitic guard in general 

 appearance, but are distinguished from it by presenting, instead of 

 the terminal cavity intended for the reception of the chambered 

 shell, a protruding and convex base." 



Miller defined the genus in the following words: — "A club- 

 shaped spathose concretion, consisting of two nearly equal longi- 

 tudinal adhering portions. Apex pointed ; base a convex but 

 ■obtuse cone. The whole formed of a series of enveloping fibrous 



1 Eeport on Cornwall, 1839, p. 83. 



2 Trans. Roy. Geol. Soc. Cornwall, xii (6), 1903, p. 406. 



3 Trans. Geol. Soc, ser. ii, vol. ii, pt. 1 (1826), pp. 45-62. 

 * Ibid., pp. 63-67. 



