ANIMALS. 97 



Spondylus Goldfussi, Miinster. Geol. Russ., vol. i, p. 224, 1845. 

 (?) Proddctus horridds, jun., J. Sow. Geinitz, Grundriss, p. 521, pi. xxii, figs. 9, 10, 1846. 

 Strophalosia.i King, An. and Mag. Nat. Hist., vol. xviii, p. 93, 1848. 

 Productus Golufussi, Miinster. De Koninck, Monog. Productus, p. 257, pi. xi, fig. 4, 



a, b, c, d, e; and pi. xv, fig. 4, a, b, 184/. 

 Strophalosia — ,, King, Catalogue, p. 9, 1848. 



Productus Morrisianus, King. Howse, Trans. T. N. F. C, vol. i, p. 257, 1848. 

 Orthothrix Goldfussi, Miinster. Geinitz, Versteinerungen, p. 14, pi. v, figs. 27, 28, 



32, 33 a, b, c (excluding figs. 29, 30, 31, 



34), 1848. 



Diagnosis. — Form sub-triangular marginally. Large valve flatly convex ; with 

 (occasionally) a shallow median furrow, and numerous long, slender, curving spines : 

 area somewhat narrow, and more or less elevated ; with a narrow deltidium : umhone 

 pointed, projecting behind the hinge, often blunted, and more or less irregularly 

 twisted. Small valve slightly concave ; with numerous declined rather long spines, and 

 a small area.^ 



Strophalosia Goldfussi is an extremely variable species, rarely two species being 

 found alike. The examples occurring at Ryhope Field-House Farm, differ from those 

 to be found at Humbleton Hill in having the large valve more rounded, and with a 

 very slight indication (in some specimens none) of a median furrow ; their area, also, 

 is not so high : in these respects they offer a close agreement with some of the German 

 specimens figured in the ' Versteinerungen.' The singular projecting umbone (PI. XI, 

 fig. 1), and elevated area (PI. XII, fig. 12 «) are features which give this species a 

 very different aspect to what any of its known congeners possess, with the exception 

 perhaps of the so-called OrtJds Wangenheimi, de Vern. {=. Aulosteges variabilis, Helm.), 

 supposing it to be a species of Strophalosia. 



The error committed by Count Miinster in naming this fossil a Spondylus is a very 

 pardonable one, considering the striking similarity it possesses, though on a small 

 scale, with some species of this genus : its twisted projecting umbone, the inequality, 

 spiny character, and form of its valves are interesting instances of the similarity ; and, 

 doubtless, the mode of attachment of both shells, that is, by their large valve or its 

 umbonal region, forms another striking point of resemblance. 



The fossil noticed by Schlotheim in the ' Taschenbuch' for 1813, p. 58, as occurring 

 at Konitz, and which he identified with the Gryphites rugosus, is, I strongly suspect, 

 the species under consideration, as it occurred to me very abundantly in this locality. 



^ One of the noticed " three Magnesian limestone species found in the neighbourhood of Sunderland." 

 (Loc. cit.) 



2 The following is the original description of this species, published by Count Miinster : " Die untere 

 tiefe Schale ist mit feinen, langen, gebogenen, iiber und durch einander liegenden Stacheln dicht besetzt ; 

 auf der obem, flachen, etwas eingedriickten Schale siad die] Stachela kurz, in der Mitte wie erhabene Punkte 

 am Rande etwas langer. Der Anheftungspunkt der Muschel war an der Schloss-seite. Wenn sie frei 

 gewesen ware, wurde ich sie fiir einen Productus gehalten haben." (Beitr'age, p. 65.) 



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