TEREBRATULA. 
Terebratula appressa, Forbes. 
Morrisia Anomioides, Davidson. 
Hab. Mediterranean (dredged from a depth of ninety-five 
fathoms); Forbes. 
An interesting Anomia-like species, discovered about 
the same time, first by Professor Scacchi, and afterwards 
by Professor Edward Forbes, during his deep-sea dredg- 
ings inthe Aigean. The ventral valve is very little beaked, 
so that the foramen, which is of large size, encroaches upon 
the dorsal valve, occupying the place of the umbo; and 
there is consequently no deltidium, The loop is short and 
spur-shaped, passing from a simple plate on each side to a 
central bifurcated process. 
Species 41. (Mus. Cuming.) 
TEREBRATULA (MorRISIA) LUNIFERA. Ter. testa tri- 
gono-orbiculart, tenuissima, hyalina, compressa, ad mar- 
ginem subindentatd, valvd ventrali paulo rostrata, 
foramine amplo, deltidio nullo ; apophyse septiformi, 
centralt. 
Tue LUNAR Morrista. Shell triangularly orbicular, 
very thin, hyaline, compressed, slightly indented at 
the margin, ventral valve a little beaked, foramen large, 
no deltidium ; apophysis septum-shaped, central. 
Terebratula lunifera, Phillippi, Enum. Moll. Sicil. vol. i. 
p- 97. pl. 6. f. 16 @ to f: 
Orthis lunifera, Philippi. 
Morrisia lunifera, Gray. 
Hab. Mediterranean ; Philippi. 
An extremely delicate hyaline shell, of rather a trian- 
gular form, puckered with indentations at the margin. 
Species 42. (Mus. Cuming.) 
TEREBRATULA (Morrista) Davipsont. Ter. testd trans- 
versim ovata, depressd, tenui, sordide albd aut fulves- 
cente, lineis concentricis incrementi crebris, prominulis, 
rostro viz nullo, foramine amplo, in valvd dorsali per- 
forato, deltidio obsoleto, valvd dorsali pland, ventrali 
convert ; apophyse brevi, calcariformi. 
Davipson’s Morrisia. Shell transversely ovate, de- 
pressed, thin, dead-white or fulvous, concentric lines 
of growth close-set, rather prominent, beak scarcely 
any, foramen large, perforated in the dorsal valve, 
deltidium obsolete, dorsal valve flat, ventral convex ; 
apophysis short, spur-shaped. 
DesLonccuames, Ann. and Mag. Nat. Hist. 1855, pl. x. 
f. 20 a to d. 
PLATE X. 
Hab. Tunis (adhering to Caryophyllia ramea); Deslong- 
champs. 
I do not see that the differences alleged to exist between 
this species and M/. Anomioides are clearly specific. Far 
greater differences may be observed in bivalves of similar 
habits, of which specimens are more abundant; as of the 
common Anomia ephippium, for example, which it so closely 
resembles externally, though minute and of different orga- 
nization. d. Davidsoni is distinguished from M. Anomio- 
ides, so far as the few specimens known permit of a dis- 
tinction being noted, by the following particulars :—The 
shell is larger and of more transverse growth, with the 
concentric lines of increase rising almost to the sharpness 
of asperities. The foramen is large, and encroaches so 
much upon the dorsal valve as to appear almost to be- 
long to it alone, and the dorsal valve is flat and irregu- 
larly indented, denoting a close attachment to the body to 
which the pedicle is affixed. 
Species 43. (Fig. a, Mus. Taylor; Fig. 6, Mus. Cuming.) 
TEREBRATULA (ARGIOPE) DECOLLATA. Ter. testd semi- 
ewculart, cuneiformi, albd, radiatim costatd, costis 
paucis, abtusis, rostro subacute trigond, brevi, ared 
latd, concavo-truncatd, foramine amplo, deltidio vix 
nullo, valvis modicé convexis, ventrali versus rostrum 
tumida ; apophyse ad cardinem utringue lobata, septis 
tribus dentiformibus radiantibus prope marginem anti- 
cam. 
THE DECOLLATED Areropn. Shell semicircular, wedge- 
like, white, radiately ribbed, ribs few, obtuse, beak 
rather sharply triangular, short, area broad, concavely 
truncated, foramen large, deltidium rudimentary, 
valves moderately convex, ventral swollen towards the 
beak; apophysis lobed on each side at the hinge, 
with three radiating tooth-like septa near the front 
margin. 
Anomia decollata, Chemnitz, Conch. Cab. vol. viii. p. 96. 
pl. 78. f. 705 a to d. 
Anomia detruncata, Gmelin. 
Terebratula decollata, Deshayes. 
Terebratula detruncata, De Blainville. 
Megathyris detruncata, D’Orbigny. 
Terebratula aperta, De Blainville. 
Terebratula dimidiata, Scacchi. ) 
Terebratula cardita, Risso. 
Terebratula urna-antiqua, Risso. 
Orthis detruncata, Philippi. 
Argiope detruncata, Deslongchamps. 
Argiope decollata, Davidson. 
