OF THE ANTWERP CRAG. 397 
slightly rounded ; dorsal margin forming a continuous curve from its highest point to 
the infero-posterior angle; ventral margin almost straight. Seen from above the out- 
line is ovate, widest in the middle, and tapering evenly to the extremities, which are 
rather obtuse ; width nearly equal to the height. End view nearly circular. Surface 
of the shell perfectly smooth. Length 35 inch (0°85 millim.). 
This differs from the typical form of the species only in being entirely destitute of 
papillose ‘sculpture. The papillose form (which, however, varies very much in its 
surface ornament) has been found in the fossil state in most of the Post-tertiary beds 
of Scotland, as well as in Norway and Canada, and by M. Bosquet in many of the 
Tertiary beds of France. In the living state it occurs plentifully in the seas off 
Norway and Great Britain and Spitzbergen, as well as in Baffin’s Bay and the Gulf of 
St. Lawrence. My memoranda of the particular bed or beds in which this form 
occurred have unfortunately been lost. 
CYTHERIDEA PINGUIS, Jones. (Plate LXII. figs. 5 a-3 d.) 
Cytheridea pinguis, Jones, Tertiary Entomostraca of England, p. 43, pl. ii. figs. 4a-4h. 
? Cytheridea fabeformis, Speyer, op. cit. p. 52, pl. 1i. fig. 1. 
Carapace, as seen from the side, ovato-triangular, highest a little in front of the 
middle; height equal to more than half the length; extremities rounded, dorsal 
margin very boldly arched, almost gibbous; ventral slightly convex; seen from above 
the outline is ovate, scarcely at all tapering to the extremities, which are rather broadly 
rounded ; the width is nearly the same throughout, and is equal to half the length. 
End view nearly circular. The shell-surface is nearly smooth, but is usually covered 
with closely-set small punctures. Length 3+ inch (0-9 millim.). 
Professor Jones’s specimens were found in the Pliocene of Suffolk. Those described 
in this memoir are from all the Antwerp beds except only that of the “ Sables 4 Bryo- 
zoaires.” It is one of the more abundant species. 
CYTHERIDEA CYPRIDIOIDES, nov. sp. (Plate LXIX. figs. 6 a6 e.) 
Carapace tumid, ovate: seen from the side the outline forms about two thirds of a 
circle, the dorsal margin being excessively arched, and the ventral slightly convex; the 
extremities are rounded, the posterior much the narrower and rather flattened; greatest 
height equal to two thirds of the length. Outline seen from above regular ovate, extre- 
mities obtuse ; width equal to more than half the length. Surface of the shell perfectly 
smooth. Length 3/5 inch (0°85 millim.). 
A few specimens of this species were found in the “Sables moyens” (zone a Bryo- 
zoaires). Iam by no means sure that the form called in this memoir C. papillosa, var. 
levis, may not be merely the male of this species. 
CYTHERIDEA MULLERI (Miinster). (Plate LXII. figs. 4 a—4 e.) 
Cythere miilleri, Minster, Jahrb. fiir Mineralogie, 1830, p. 62, and Neues Jahrb. 1835, p. 446 
(fide Jones and Bosquet). 
32 
