137 



Remarks. — This species difters from Lorica volvox and L. affinis 

 in the strong radial ribbing of the lateral areas and the great 

 number of the longitudinal ribs in the pleural area, but it corre- 

 sponds with L. affinis in the compression of the side slopes The 

 decussation of the interspaces present in L. affinis is absent in 

 this species. 



2. Lopiea afflnis, n. sp. Pi. iv., fig. 7. 



One example of median valve. 



General Appeara7ice. — Carinated, side slope slightly curved^ 

 though almost straight, color pale yellowish-brown 



Lateral Area — Distinctly raised, ornamented with six radial 

 •ows of somewhat distant pustules which rise out of ver}^ shallow 



ridges. 



Pleural Area Longitudinally ribbed with twelve narrow, 



but strong ridges ; the interspaces are fully three times the 

 width of the ribs, and nearly flat ; these ridges have a slight 

 tendency to granulation, but the transverse stria? which produce 

 the same appearance in its congener, Lorica volvoo^, are not dis- 

 cernible in this species. The megalopores are very pronounced, 

 giving under a powerful lense a strongly decussated appearance. 



Measurement. — The greatest width between the slopes is 

 20 mm.; width of slopes, 10 mm ; length of slopes, 15 mm.; 

 divergence, 90". 



Insertion plates have broken away ; there is no indication of 

 teeth 



Remarks. — This species so closely resembles Lorica volvoo:, Rve, 

 that it almost justifies its being referred to that living species; 

 the most marked difference is in the compression of the valves. 

 In volvox there is a slight widening or separating of the two 

 slopes at their extremities, whereas in the species now described 

 there is a slight drawing together. The other differences are tlie 

 absence of transverse strije (but this may be accounted for 

 through the wearing of the shell) and the more decussated effect 

 produced by the megalopores. Its close affinity to Lorica volvox^ 

 Reeve, is undoubted. 



3. Lorieella gigantea, n. sp. Pi. iv., fig. 3. 



One specimen of anterior valve only. 



General Appearance — Color dirty- white or wainscot-brown, 

 shape exceptionally broad (nearly twice as broad as long) and 

 very flat, anterior third of valve curved downwards, other two- 

 thirds practically straight except at the apex, which is very 

 slightly elevated. 



ScnAptnre. — Radially ribbed with very numerous, pronounced, 

 bifurcating riblets, which are crossed by about 26 concentric 

 wrinkles ; while these are clearly defined, some are more so than 



