KNOWN SPECIES OF MARINE OSTRACODA. 371 
Lucid spots about four, in a transverse row, with one or two more detached from and in 
front of the main group. 
Hab. Hunde Islands, 25-30 fathoms (Dr. Sutherland). Norway (Messrs. M‘ Andrew 
and Barrett) British north-eastern and north-western coasts, 20-46 fathoms. 
Length 35 in. (‘84 mm.). 
A species allied to Cytheridea pinguis, Jones. Of frequent occurrence both on the 
eastern and western shores of the North Sea. It is one of the commonest of living 
species in the deep water off the Northumberland and Durham coasts. I have also seen 
fossil specimens collected by Messrs. Robertson and Crosskey, of Glasgow, from the 
glacial clay of that district. 
6. CyTHERIDEA MULLERI, Von Miinster. (Pl. LVIII. fig. 11, a—d.) 
Cythere miilleri, Von Minster, Leonhard und Bronn’s Jahrbuch (1830), p. 62; and Neues Jahrbuch, 
&c. (1835), p. 446. 
Cytherina miilleri, Reuss (1850), Haidinger’s Abhandl. Band iil. p. 55, t.8. fig. 21. 
Cytheridea miilleri, Bosquet, Ent. Fossil. des Terrains Tertiaires, p. 39, pl. 2. fig. 4 a—f. Jones, Monog. 
Tert. Entom. p. 41, pl. 5. figs. 4,5; pl. 6. figs. 10,11,12. Egger, Ostrak. der Miocan-Schicht. 
p- 18, t. 2. fig. 7. Speyer, Ostr. der Casseler-Tertiarbild. p. 48, t. 1. fig. 8. 
Valves elongated, siliquose, tapering to the posterior extremity, twice as long as broad. 
Anterior border rounded, and armed with a variable number of sharp spines. Dorsal 
margin arched, and forming a regular curve as far as the posterior ventral angle, which 
is somewhat produced. ‘The ventral margin is straight or gently sinuated. Dorsal 
profile oval. ‘The surface of the shell is marked with subquadrate pits arranged in lon- 
gitudinal series. 
Length 3/5 in. (74 mm.). 
Hab. Mouth of Hermus, Smyrna; Australia. 
Genus Cyruere, Miiller. 
Carapace mostly convex, varying in outline, but mostly oval or irregularly oblong, 
and highest beneath the anterior hinge, the anterior (and sometimes the posterior) 
hinge forming indistinct angles on the dorsal margin. The hinge occupies the middle 
portion of the dorsal margin, and consists, on the right side, of a ridge with two ter- 
minal teeth, the anterior of which is the most strongly developed. The hinge-margin 
of the left valve exhibits two fossze for the reception of the teeth of the right valve. 
The anterior fossa sometimes forms a complete circular perforation of the marginal 
plate. Between the terminal depressions there is a longitudinal groove adapted to the 
bar of the opposite valve, and also two terminal projections, much smaller than those 
of the right valve. The bar and furrow are in many cases obsolete. The edges of the 
carapace are often produced into thin projecting laminz, especially on the anterior and 
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