ERYCINID ZA. 991 
BORNIA, Philippi, 1836. Shell elongately oval, with slightly 
projecting beaks, almost equilateral, surface finely concentrically 
striated ; hinge with three teeth in the left valve, two small ante- 
rior and one somewhat remote and elongated posterior, right 
valve with only two diverging elongated cardinal teeth; carti- 
lage situated in a groove in front of the posterior teeth ; muscular 
impressions faintly marked. KK. corbuloides, Phil., occurs recent 
in the Mediterranean and the Atlantic, and fossil in miocene beds 
of Italy and the Vienna Basin. KX. seminula, Phil. (exx, 93-95). 
CYCLADELLA, Carp., 1865. Shell resembling Gidalina in form, 
thin, umbones flattened ; ligament external, very thin; the car- 
dinal teeth lie in the curve of the hinge-line, together with the 
laterals, which are distant. 
PYTHINA, Hinds. (Myllita, d’Orb. and Recl.) Shell trigonal, 
divaricately sculptured ; ligament internal; right valve with two 
lateral teeth, left with one cardinal and two laterals. 13 sp. New 
Ireland, Australia, Philippines. Fossil,2 sp. Hocene; France, 
Java. P. Deshayesiana, Hinds (cexx, 96). 
Cyamium, Philippi, 1845. 
Distr.—3 sp. Patagonia, Northern Europe, U.S. Fossil, 1 sp. 
Tertiary; Europe. C. Aniarcticum, Phil. (exx, 97). 
Shell oblong; hinge-teeth, 2-2; ligament double; cartilage in 
a triangular groove behind the teeth in each valve 
TURTONIA, ‘Hanley. Shell oblong, inequilateral, anterior side 
very short; ligament concealed between the valves; hinge-teeth 
9-2. Animal with the mantle open in front ; foot large, heeled ; 
siphon single, slender, elongated, protruded from the long end of 
the shell. Greenland, Norway, Britain; in pools and crevices of 
rocks between tide-marks, and in the roots of sea-weeds and cor- 
allines. Mr. Thompson obtained them from the stomachs of 
mullets taken on the northeast coast of Ireland. TZ. minuta, 
Hanley (cxx, 98, 99). 
HINDSIELLA, Stol., 1870. (Hindsia, Desh., 1860. Vasconia, 
Fischer.) Shell elongately subtriangular, nearly equivalve, with 
the lower margin insinuated, hinge with one or two (generally 
one in the right, two in the left) minute cardinal teeth in each 
valve; ligament external, supported by thin fulcra; muscular 
impression narrow, elongated, pallial line rather broad, simple. 
C. lobata, Desh. (ecxx, 100). Grignon. 
Tuecoponta, A. Ad., 1864. 
Distr.— Th. Sieboldi, A. Ad. China Seas. 
Shell oblong, very inequilateral, the anterior part being 
shorter than the posterior, concentrically suleated ; hinge in the 
left valve with two diverging cardinal teeth with a cup-like pro- 
jecting fold between them, a single posterior lateral tooth present ; 
