42 BRITISH PERMIAN BRACHIOPODA. 



Corbusen, &c. Baron Schauroth has found it abundantly in the Zechstein dolomit of 

 Possneck, where it appears associated with the same species found at Humbleton and in 

 some other of our magnesian shell limestone localities. 



In 1839 Miinster figured, under the name of Spondylus Goldfussi, a specimen evidently 

 belonging to the shell under description. It is longer than wide, concavo-convex, and 

 covered with spines ; but as much of the beak and area was obscured by matrix, the 

 German author was not quite certain as to the exact place his shell should occupy ; so 

 that, while placing it in Spondylus, he at the same time took care to add, that had it 

 been free he should have taken it for a Productus. The shell under description is the one 

 very generally known on the Continent to represent the species of the German Count, 

 which either did or did not possess a mesial furrow in the larger valve, so that this last- 

 named feature could not be considered as a character of any specific importance. 



In 1842, Dr. Geinitz described and figured a small shell under the name of Orthis 

 excavata} It was longer than wide, with a straight and large triangular area, narrow 

 fissure, pointed beak, and plano-convex spinulose valves. This shell has appeared to me, 

 as well as to Professor De Koninck and Mr. Howse, to be only a young condition of 

 Strop/ialosia Goldfussi, and in our opinion should therefore be placed among the synonyms 

 of that species ; but Professor King dissents from this view, and seems disposed 

 to consider it not only a distinct species, but also the same as that subsequently named 

 Prod. Lewisiana by Professor De Koninck, 1846. At a later period, in 1848, it is true 

 Dr. Geinitz published figures of his so-termed excavata, differing somewhat from the 

 original type, and which might be either taken for S. Goldfussi or its variety S. Lewisiana, 

 and from this unfortunate coincidence much of the confusion and uncertainty has arisen 

 that prevails at present among these Strophalosias. 



I therefore consider it necessary to restrict my inferences upon this matter to the 



1 la the c Neues Jahrbuch' for 1842, p. 5/8, figs. 12 and 13 a, b, Dr. Geinitz has omitted to represent 

 the tubercular prominences left by the broken spines, so that his figures might give the idea of a 

 smooth species ; but in the accompanying description the author does not omit to allude to 

 their existence. Professor King kindly forwarded for my examination three or four exam- 

 ples closely agreeing with Geinitz's figure, and which he had obtained when in Germany; 

 but after a minute examination of these (evidently young shells) with fig. 3 of my PI. Ill, 

 which certainly belong to Minister's species, I could perceive no differences of sufficient 

 importance to warrant my supposing them specifically distinct. In a letter written by Dr. Geinitz to 

 Professor King, dated the 11th of March, 1857, the German author states thztStroph. Goldfussi "is without 

 sinus," which observation cannot be considered strictly correct, for although it may not be perceptible on 

 certain individuals, it exists to a greater or lesser degree on the larger number. Dr. Geinitz also mentions 

 that his Orthis excavata of 1842 is the same as the one described under the name of Lewisiana in 1846, 

 and by Professor King under that of Stroph. excavata in 1850 ; but I fear I must object to that interpreta- 

 tion. Dr. Geinitz further observes that Stroph. excavata possesses "a sinus more or less only in the upper 

 Zechstein," but his figures of O. excavata show none; and in the character published in 1842, he 

 distinctly states that the larger valve is regularly convex, and that the smaller one is similarly concave, and 

 there is no mention of any sinus. 



