398 DE. G. S. BEADT ON THE OSTEACODA 



Cytherina miilleri, Eomer, Neues Jahrb. fiir Mineralogie, 1838, p. 516. t. vi. fig. 6 (fide Jones and 



Brady); Reuss, Haidinger's Abhandl. 1850, p. 55. pi. viii. fig. 21. 

 Bairdia hagenovA, Reuss, Zeitsct. d. deutsch. geol. Ges. 1855, p. 60, pi. ix. fig. 93. 

 Cytheridea heterostigma, Reuss, ibid. p. 60, pi. ix. fig. 94. 

 Cytheridea miilleri, Bosquet, Entom. foss. terr. Tert. France, p. 39, pi. ii. fig. 4 ; Jones, Tert. Entom. 



England, p. 41, pi. v. figs. 4a-4c & 5, pi. vi. figs. 10a, 106, & 11-13; Egger, Die Ostrak. der 



Miocan-Scliicht. Orenburg, p. 18, pi. ii. fig. 7 ; Speyer, Die Ostrac. der Casseler Tertiarbild. 



p. 48, pi. i. fig. 8; Brady, Trans. Zool. Soc. Lond. v. p. 371, pi. Iviii. figs. Wa-d. 

 Cytherina intermedia, Reuss, Haidinger's Abbandl. ui. p. 86, "pi. xi. fig. 12. 

 Cytherina seniinulum, Eeuss, ibid. p. 59, pi. ix. figs. 5-8. 



Carapace of the female subovate, tumid : seen from the side, ovate-triangular, highest 

 a little in front of the middle ; height equal to rather more than half the length ; ante- 

 rior extremity well rounded, posterior narrowed, obliquely rounded, and often somewhat 

 exserted at the inferior part, forming a rounded obtuse angle ; dorsal margin arched, 

 usually more or less angulated in front of the middle ; ventral margin nearly straight. 

 Seen from above, ovate, sides subparallel, tapering abruptly to the extremities, width 

 less than half the length. End 'riew very broadly o^■ate. The surface is marked with 

 numerous impressed rounded punctures, which often tend to arrange themselves in 

 curved transverse furrows, and on the ventral surface to coalesce into longitudinal 

 furrows ; the margins are often entirely smooth ; but frequently the anterior border is 

 armed below the middle with a row of six or eight sharp spines on each valve ; the 

 posterior extremity also sometimes bears a single spine at its lower angle ; this is 

 situated on the light valve. The shell of the male is, as usual, more compressed and 

 elongated. Length -^ inch (0-9 millim.). 



This is one of the most common species in the Antwerp beds, and has been found in 

 all of them except the zone of Isocardium cor. ; it has also been found in most of the 

 Tertiary formations of Europe, in Austria, Bohemia, Hesse, Westphalia, France, and 

 the Netherlands (Eocene), in Touraine (Miocene) and in the Netherlands (Pliocene) ; 

 it has also been noticed by Professor Rupert Jones in many of the Tertiary beds of 

 England, and in a Tertiary Clay from Australia. I have myself seen recent specimens 

 from Smyrna, the Levant, and Australia. 



Genus Loxoconcha, G. O. Sars. 

 Valves nearly equal, subrhomboidal, and mostly flexuous in outline ; surface smooth, 

 or marked with concentrically arranged impressed puncta ; or with polygonal fossae, 

 often also with minute circular papillae ; ventral margin usually forming a prominent 

 compressed keel behind the middle ; postero-superior angle obliquely truncate ; hinge- 

 joint formed by two small teeth at the extremities of the hinge-line of each valve. 

 Limbs of the animal slender and colourless. Upper antennae very slender, 6-jointed, 

 the last joint very long, linear, and bearing long simple setae ; lower antennae 4-jointed, 

 the thii-d joint long and narrow. Flagellum long and biarticulate. Mandibular palp 



