PARADOXOSTOMA. 217 



7. Paradoxostoma tenerum, nov. sp. Plate XVI, figs. 21, 22. 



Almost exactly like F. flexuosum, except that, when seen laterally, the anterior 

 extremity is more widely rounded, and the superior margin more boldly arched in the 

 middle ; the dorsal aspect presents also a more compressed outline, while the surface of 

 the shell is slightly papillose, with hair-like markings along the ventral margin. The 

 length is also greater, being about -^th of an inch. Yet notwithstanding these differences- 

 we have still some misgivings as to its title to rank as a distinct species. 



Distribution. Fossil. — Scotland : Dumbarton, Cartsdyke, Dalmuir. 



8. Paradoxostoma arcuatum, Brady. Plate XVI, fig. 25. 



1868. Paeadoxostoma ARCUATUM, Brac?y. Monog. Rec. Brit. Ostrac, p. 461, pi. 



XXXV, figs. 37, 38. 



Carapace, seen from the side, oblong, subtriangular, highest in the middle, height 

 equal to a little more than one third of the length, extremities moderately rounded, 

 superior margin well and evenly arched, inferior almost straight. Seen from above, 

 compressed, ovate, widest behind the middle, width equal to one fourth of the length. 

 Shell quite smooth. 



Length, -^g-th of an inch. 



Distribution. Becent. — West of Ireland, Shetland. 



Fossil. — Scotland : Raised-beach at Oban. 



i?fem7y 4— CYPRIDINAD^. 



Genus 1 — Asterope, Philippi. 



Shell subcylindrical, beak not at all produced. Upper antennae six-jointed ; in 

 \he female short and thick, and bearing several subequal,, terminal setas of moderate 

 length; in the male more elongated, two of the terminal setse of excessive length, 

 the antepenultimate joint bearing a stout and densely setose auditory filament. Second 

 joint of the natatory branch of the lower antennae in the tnnle elongated, in the 



28 



