VI. — Observations on the Genus Actinocamax. 

 By Mr. J. S. MILLER, A.L.S., &c. 



[Read May 2d, 1823.] 



riAVING lately had the honour of submitting to the Geologial Society some 

 observations on the Eelemnites, I proceed to lay before them the result of my 

 inquiries with regard to another class of organic remains nearly connected 

 with these ; — namely, those spathose bodies which resemble the belemnitic 

 guard in general appearance, but are distinguished from it by presenting, 

 instead of the terminal conical cavity intended for the reception of the cham- 

 bered shell, a protruding and convex base ; they are of familiar occurrence 

 in the chalky strata. 



These bodies have been considered by some writers as true Belemnites, 

 by others as Echinital spines. The object of the following communication is to 

 show, by a minute comparison of their structure with that of these bodies, 



1st, That they have no analogy with Echinital spines. 



2dly, That they present very strong analogies in the minutest points of their 

 internal structure, &c., with the guards ©f the Belemnites ; but yet having 

 evidently never possessed a chambered shell, must be separated from them. 



Srdly, That they were probably however, like the Belemnites, appendages 

 of some distinct family of the same order of Cephalopodous Mollusca, possess- 

 ing the same position and use with the bone of the Sepia and guard of the Be- 

 lemnite ; exhibiting a new link in the series of the appendages pecuhar to 

 Lamarck's third division of this order. 



Genus. ACTINOCAMAX. 

 Gen. Char. A club-shaped spathose concretion, consisting of two nearly 

 equal longitudinal adhering portions. Apex pointed ; base a convex but 

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



Animal unknown : but as these fossils occur in the strata which contain the 

 remains of marine animals, we may infer that it also was an inhabitant of the 

 sea. 



