Prof. W. King's Notes on Pennian Fossils. 263 



genus Aulosteges. All the German specimens I have seen assist 

 in lending considerable support to this conjecture ; for they show 

 more or less traces of a wide irregular area and a closed 

 tissure*. "With regard to its mode of articulation, the following 

 expression may still be taken as correct : — " 1 can say with safety 

 that it is not furnished with any teeth ; it consequently cannot 

 be a Strophalosia " (Monograph, p. 92). The conclusion em- 

 bodied in this sentence is completely confirmed by the form of 

 the reniform impressions, which, on referring to the figure here 

 given {vide PI. XII. fig. 0), will be seen to agree completely with 

 those eharacterijitic of Productus, and to be altogether different 

 from those peculiar to Strophalosia. 



^^'ith regard to the genus Aulosteyes, I possess some good 

 determinable specimens of the typical species from the Permian 

 beds of Mont Grebeni near Orenburg, obligingly presented to 

 me by Col. Ilelmerson through Sir Roderick Murchison ; Mr. 

 Davidson has also kindly favoured me with tracings of Col. Hel- 

 merson's figures of the same species, illustrative of his original 

 memoir ; 1 am therefore in a position to speak with more con- 

 fidence than formerly on the genus. I have no doubt whatever 

 of its being distinct from Strophalosia, since it is not furnished 

 with any teeth — structures which are strictly diagnostic of the 

 last-named genus — inasmuch as species may be tx'uly denti- 

 gerous, and yet have a concealed or an almost obsolete area, as 

 in Strophalosia subaculeata. 



There is yet one point to be cleared up in connexion with 

 Aulosteges. Do its reniform impressions project decidedly in 

 front of the median plate, as in Strophalosia, or no further than 

 about the extremity of this plate, as in Productus ? f I have 

 represented the interior of the small valve of ? Aulosteges umbo- 

 nillatus, on which it will be seen these structures are situated as 

 in Productus : if it could be positively affirmed that this species 

 is a true Aulosteges, the reniform impressions would ally the 

 genus more closely with Productus than Strophalosia. 



Genus Strophalosia, King. 

 Strophalosia parva %, King. 



This species has not yet been noticed as occurring in Germany ; 

 but I have seen a specimen (cast) adhering to the inner surface 



* I formerly suspected the closed fissure to be a notch in the area 

 caused by the cardiual process pressing against «h<it I then termed the 

 "flattened (arca-hke) space." 



t Vide my Monoirraph, p. 05. and pi. 1 1 . fip:. 1 0, and pi. 1 2. figs. 5, 9, 14 

 & 30, where these difi'ereuces are described and figured. 



+ Vide op. cit. p. l()-2. pi. 12. fig. 3.i. 



