ANIMALS. 129 
TRIGONOTRETA MULTIPLICATA, J. de C. Sowerby. Plate VIII, figs. 15, 16, 17, 18: 
SPIRIFER MULTIPLICATUS, J. de C. Sow. Sedgwick, Trans.. Geol. Soc., 2d series, vol. 11, 
p. 119, 1829. 
= == a De la Beche, Geol. Man., Ist ed., p. 384, 
1831; Germ. Transl. p. 459, 1832; 3d 
Eng. ed., p. 573, 1833. 
a = sf Phillips, Encye. Met., vol. iv, p. 617, 1834. 
— — ah Morris, Catalogue, p. 129, 1843. 
— = De Verneuil, Bull. Soc. Géol. 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. 
— a= Howse, Trans. T. N. F. C., vol. i, p. 254, 1848. 
Diagnosis—Semi-oblong marginally; about half an inch in width, and three 
eighths in length; with generally ten rather prominent obtusely-rounded ribs. Swrface 
with prominent lines of growth. Puwnctures large, giving the valves a coarsely 
eranulated appearance. Large valve nearly half as wide as it is high; somewhat 
rounded: wmbone moderately incurving: area one third of its width in height: jissure 
rather large and open: median plate elevated, and extending to nearly the centre of the 
valve. Small valve moderately rounded: median vib depressed; and nearly thrice 
the width of those immediately adjoming 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 foregomg 
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 ina fragment of Magnesian Limestone brought up bya 
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 MULTIPLICATUS, 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. Swrface 
with regular and rather distant lines of growth, and finely granulo-punctated. Large 
' Named im compliment to Mr. T. Rupert Jones, who has in the kindest manner described the 
Microzoa of the present Monograph. 
