408' G. C. Click — Note on Acti)iocamax, etc. 



laminse." The only species mentioned, A. verus, is characterized 

 as follows : — "A club-sliaped spathose semitransparent horn-coloured 

 concretion ; base convex, obtuse, conical ; apex submamillar. Sides- 

 depressed towards the lower end, showing two longitudinal, towards 

 the apex branching, impressions of blood-vessels." This w^as stated 

 to be from the ''Chalk, and sometimes inclosed in the flints imbedded 

 in it," of Kent, Wiltshire, and Sussex. 



Although subsequently united by some authors with the genus 

 BelemniteUa and by others merged in the genus BeJemnites, Actino- 

 camax is now usually employed as a distinct genus to include certain 

 belemnites from the Chalk. 



Mr. C. D. Sherborn has, however, called my attention to H. F. 

 Link's " Beschreibung der Naturalien-Sammlung der Universitat zu 

 Eostock," of which the third part, published 25tli December, 1807, 

 is devoted to " Fossile Ueberbleibsel organischer Kiirper, sogenannte 

 Versteinerungen." After defining (p. 8) the genus Belemnites as 

 "a conical, internally radiate crystalline shell, within which is 

 found another many-chambered (the alveolus),"' Link proceeds to 

 describe (p. 9) a new genus Atractilites thus: — ^"A spindle- 

 shaped, internally radiate crystalline shell, without alveolus," the 

 only species given being A. belemniticus, respecting which he states : 

 " the spindle-shaped Belemnites are quoted by many authors, but 

 often confounded and not exactly described. We possess specimens 

 completely pointed at each end. On one there are distinct traces 

 of a foliaceous texture, in other respects they are quite similar to 

 the usual Belemnite. I have broken a specimen and found 

 internally the radiate structure of the Belemnite, but absolutely no 

 alveolus, therefore they cannot be referred to the former genus " 

 \_Belemnites^. 



From the extracts given above it is quite clear that Miller's 

 Actinocamax is a synonym of Link's Atractilites. Link's name has 

 priority of publication, his work having been published in 1807, 

 whilst Miller's paper was not read before 1823, and not published 

 before 1826. The name must not, however, be confounded with 

 the Belemnoid genus Atractites of GiimbeP from the Lower Lias 

 and Upper Trias. 



' The term ' alveolus ' is here used for the chambered part of the shell, but this is 

 now knoTMi as the phi-agmocone, the term ' alveolus ' being applied to the conical 

 cavity in the guard that receives the phragmocone. 



* As Link's work is very rare we have thought it advisable to give the description 

 in Link's own words ; it is as follows : — 



"Atractilites. Atractilit. Eine spindelformige, iuwendig strahlig krystallisii'te 

 Schale, ohue Alveole. 



" A. belemniticKs. Belemnitischer Atr. Die spindelformigen Belemniteu werden 

 von vielen Schriftstellern angei'iihrt, aber oft verwechselt und nicht genau beschrieben. 

 Wir besitzen an beideu Endeu vollig zugespitze Exemplare. An dera eineu bemerkt 

 man deutliche Spm-en einer blattrigen Textm', sonst sind sie den gewohnlicheu 

 Belemniteu ganz ahnlich. Ich habe ein Stiick zerschlagen und inwendig die 

 strahlige Bikluug der Belemniteu aber durchaus keine Alveole getuuden, daher man 

 sie nicht zu der vorigen Gattung bringen kaun." 



^ C. W. Giimbel: " Geognostische Beschreibung des bayerischen Alpengebirges," 

 etc., 1861, p. 475. 



