70 Professor T. T. Groom — New Trilohite from Malvern. 



^ V. — On a new Trilobite from the Bicttonem&.-&b.mje>& of the 



Malvern Hills. 



By Professor Theodore T. Groom, M.A., D.Sc, F.G.S. 



"^ Aoanthopleurella Grindrodi, gen. et sp, nov, 



IN the collection made by the late Dr. Grindrod, now in the 

 Geological Museum at Oxford, there is a minute species of 

 trilobite, represented by two specimens, obtained from the Dictyonema- 

 ct) shales of the Malverns. This form was referred by Dr. Callaway to 

 (^^ Shumardia (Conophrys) Salopiensis, Call. ; ^ but a careful study of 

 the two specimens, aided by the removal of a small fragment of 

 shale which partly concealed the more complete example, has shown 

 the distinctness of the trilobite from Shumardia, and from any 

 other genus known to the writer. Owing to the kindness of 

 Professor Sollas I have been enabled to make a thorough examination 

 of the specimens. The preservation is fairly good, but much of the 

 actual test has been lost, and both fossils are largely in the form 

 of internal casts. In the more complete but somewhat smaller 

 example, which may be taken as the type-specimen, the whole 

 trilobite is preserved (Fig. 3) ; in the second sjDecimen little more 

 than the thorax and pygidium is seen (Fig. 4). The following 

 description refers to the type-specimen : — 

 V Head smooth, semi - elliptical ; frontal and lateral margins 

 descending somewhat suddenly ; genal angles acute. Glabella 

 fairly convex, smooth, broad in front, reaching the margin (which 

 here projects slightly beyond the cheeks), rather more than one-third 

 of which it occupies ; narrowing rapidly behind to the neck-furrow, 

 behind which it expands again to form a well-pronounced and rather 

 broad neck-lobe; separated from the smooth cheek by a deep and 

 fairly broad axal furrow with a rounded floor; neck-furrow not 

 strongly marked on the glabella, but well-pronounced on the free 

 cheeks, to the posterior margin of which it is parallel ; on the inner 

 side it unites with the axal furrow, and on the outer extends nearly 

 to the genal angle, and much resembles one of the pleural furrows; 

 cheeks in front of the neck-furrow rising up steeply to their greatest 

 height ; no traces visible of other furrows on the glabella, or of eyes, 

 or facial sutures on the cheeks. Length of head, 0'41 millimeter ; 

 breadth, 1*12 millimeter. 



Thorax slightly narrower than the head, and longer than either 

 head or pygidium ; consisting of four segments. Axis very 

 convex (Fig. 2), occupying some two-fifths of the width of the 

 thorax in front, and gradually diminishing in breadth behind ; 

 inflated in each segment, the inflated portions being separated by 

 rounded depressions, and extending to the pleurae in the form of 

 ridges directed obliquely forwards, one on each side. Pleurse 

 straight for most of their length, depressed near the axis (Fig. 2), 

 especially in the first rings of the thorax, the depression gradually 



1 Quart. Journ. Geol. Soc, 1877, vol. xxxiii, p. 660. 



