ANIMALS. 99 



somewhat arranged in lines, radiating and curving outwardly from the nucleus. 

 Ventral valve concave, with very many declined longish spines having the same arrange- 

 ment as those on the dorsal valve ; umbone small, rounded, somewhat incurved, and 

 slightly impressed."' 



Stroplialosia excavata differs from S. Goldfussi in the roundness of its marginal outline, 

 the regular and strong convexity of its large valve, the rounded form of its umbone, 

 the curvedly radiating arrangement of its spines, and the smaller size of its area. 

 The arrangement of the spines constitute a capital distinctive character for this species, 

 compared with its associates ; and I regret that none of my figures represent it so 

 clearly as could be wished : some of the figures in the ' Versteinerungen' (vide pi. v, 

 fig. 30 ; pi. vi, fig. 20 a) have an advantage over mine in this respect. My description 

 characterises the large valve as having the " area small and slightly elevated." This 

 must be taken in comparison with the area of Stroplialosia Goldfussi. 



In my ' Catalogue ' this species is named Stroplialosia spinifera ; but it is there 

 suggested to be the Ortliis excavata of Geinitz, — a suggestion confirmed by the 

 publication of the ' Versteinerungen.' It requires to be mentioned, however, that I 

 entertain a suspicion of some of the shells figured in this work, under the latter specific 

 name, belonging to Stroplialosia Goldfussi, and particularly the one originally given by 

 Dr. Geinitz in the 'Neues Jahrbuch' (1842, pi. x, figs. 12, 13) ; but as certain of the 

 specimens represented in the ' Versteinerungen' (pi. v, figs. 30, 37 ; pi. vi, fig. 20) are 

 undoubtedly the same as my S. spinifera, and as my learned co-operator has identified 

 his Ortliis excavata with Dr. de Koninck's Productus Leivisianus and P. Geinitzianus, in 

 which I entirely agree with him, I readily cancel my name and replace it by the one 

 herein adopted. 



Stroplialosia excavata is found at Humbleton, Dalton-le-Dale, Tunstall Hill, Hylton 

 North-Farm, and Tynemouth. Dr. Geinitz records its occurrence at Possneck, Konitz, 

 Liebenstein, and Hirschberg in the Zechstein. Should the so-called Grypliites 

 aculeatus, jun., figured by Schlotheimin the ' Taschenbuch, (vol. vii, pi. iv, fig. 3, 1813) 

 be the same, it may also be said to occur in the Kupferschiefer of Schmerbach. 



Strophalosia Morrisiana,^ King. PI. XII, figs. 18, 19, 20, 21, 22, 23, 24, 25, 



26, 27, 28, 29, 30, 31, 32. 



(?) Gryphytes aculeatus, Jun., Schl. Akad. Miinch., vol. vi, p. 29, pi. viii, fig. 15 a, b, 



fig. \6a,b, 1820. 

 (?) Producta — " perhaps a new species," Phillips. Philosophical Mag., N. S., vol. iv, 



p. 401, 1828. 



1 King, 'Catalogue,' p. 9. 



2 In naming this shell after the author of the ' Catalogue of British Fossils,' I evince my respect for one 

 who has frequently assisted me in my labours, and to whom, in a great measure, is due the publication of 

 this Monograph by the Palseontographical Society. 



