ANIMALS. 159 



Trigonotreta multiplicata, /. (le C. Sowerhy. Plate VIII, figs. 15, 16, 17, 18. 



SpiuiiER JiULTiPLiCATUS, J. de C. Sow. Sedgwick, Trans. Geol. Soc, 2d series, vol. iii, 



p. 119, 1829. 



— — „ De la Beclie, Geol. Man., 1st ed., p. 384, 



1831; Germ. Transl, p. 459, 1832; 3d 

 Eng. ed., p. 573, 1833. 



— — „ Phillips, Encyc. Met., vol. iv, p. 617, 1834. 



— — „ Morris, Catalogue, p. 129, 1843. 



— — „ De Yerneuil, Bull. Soc. Geol. de France, 2""* 



serie, t. i, p. 28, 1844. 



— — „ Geol. Russ., vol. i, p. 221, 1845. 



— — „ Tennant, Strat. List., p. 88, 1847. 



— — „ King, Catalogue, p. 8, 1848. 



— ~ „ Howse, Trans. T. N. F. C, vol. i, p. 254, 1848. 



Diagnosis. — Semi-oblong marginaily ; about half an inch in width, and three 

 eighths in length ; with generally ten rather prominent obtusely-rounded ribs. Surface 

 with prominent lines of growth. Punctures large, giving the valves a coarsely 

 granulated appearance. Large valve nearly half as wide as it is high ; somewhat 

 rounded : umbone moderately incurving : area one third of its width in height : fissure 

 rather large and open : median plate elevated, and extending to nearly the centre of the 

 valve. Small valve moderately rounded : median rib depressed ; and nearly thrice 

 the width of those immediately adjoining it. 



Trigonotreta multiplicata, so designated in order to preserve a specific name given 

 by Mr. Sowerby to an undescribed fossil of the present genus, noticed in Professor 

 Sedgwick's paper, closely resembles the last species, as will be seen by the foregoing 

 diagnosis ; but differs from it in having the valves more rounded ; the ribs smaller, 

 obtusely rounded, and more numerous ; the umbones a little more gibbous ; and the 

 median rib in the flat valve wider and flattened. 



The present species has only occurred to me in the Shell-limestone at Tunstall, 

 where it is not common ; and in a fragment of Magnesian Limestone brought up by a 

 fisherman's line from the sea-bottom, about thirty miles from land, off the coast 

 of Northumberland. 



Trigonotreta Jonesiana,' King. Plate VIII, fig. 19. 



SpiRiFER JIULTIPLICATUS, J. de C. Sow. {partim). King, Catalogue, p. 8, 1848. 



Diagnosis. — Subglobular in form ; about three eighths of an inch in width, and a 

 little less in length ; with from eight to ten rather small evenly -rounded ribs. Surface 

 with regular and rather distant lines of growth, and finely granulo-punctated. Large 



1 Named in compliment to Mr. T. Rupert Jones, who has in the kindest manner described the 

 Microzoa of the present Monograph. 



