CONCHOLOGY. 
Chap. IV. 
Caffifica- 
tion of 
Shells. 
CHAP. IV. CLASSIFICATION OF SHELLS* 
399 
Caflifica- 
tion of 
Shells. 
ao 
Claffifica- 
tion. 
SHELLS are divided by Linnaeus into multivalve, 
bivalve, and univalve. In the following claflification 
the fame arrangement will be adopted ; and we lhall 
firft exhibit in one view the characters of each genus, 
in the original language of Linnaeus, with a tranflation 
oppofite, for the fake of the Englillr reader ; fo that 
the genus of any (hell may be eafily determined. In 
defcribing the fpecies, we (hall obferve the utmofl bre- 
vity, giving fuch characters only as are neceffary to af- 
ford precife marks of diftinCtion. In arranging the 
fpecies under each genus, the Britilh fpecies will be 
diltinguilhed with an aiterifk 5 fo that, with the ad- 
vantage of a general claflification, this will anfwer the 
purpofe of a Britilh conchology. 
GENERIC CHARACTERS. 
I. MULTIVALVE SHELLS. 
Generic 1 . Chiton. Animal doris. Tefice plures, fecun- 
charadter dum longitudinem libi appofitae dorfo incumbentes. 
of multi- 
valvcs. 2. Lepas. Animal triton. Telia ball affixa multi- 
yalvis : vaivis inasqualibus eredlis. 
3. Pholas. Animal afcidia. Telia bivalvis divari- 
cata, cum minoribus accefforiis difformibus : cardo re- 
curvatus cartilagine cennexus. 
1. C. Animal inhabiting the Ihell a doris. Shell 
confilling of feveral fegments or valves difpofed down 
the back. 
2. L. Animal a triton. Shell affixed at the bafe, 
and confining of many unequal eredl valves. 
3. P. Animal an afcidia. Shell bivalve, divaricate, 
differently (haped ; acceffory valves : hinges bent back, 
united by a cartilage : beneath the hinge, internally, is 
an incurved tooth. 
II. BIVALVE SHELLS. 
O!" bivalves 4* Mya. Animal afcidia. Telia bivalvis hians, ut 
plurimum, altera extremitate : cardo dente (plerifque 
uno) folido, craffo, patulo, vacuo ; nec inferto teftae 
appofitae. 
5. Solen. Animal afcidia. Telia bivalvis oblon- 
ga, utroque latere hians. Cardo dens fubulatus refitx- 
iss, faepe duplex, non infertus teltae appofitae; margo 
lateralis magis obfoletus. 
6. Tellina. Animal tethys. Telia bivalvis, an- 
te ri us hinc ad alterum latus flexa. Cardinis dentes ut 
plurimum ties : laterales plani alterius teltae. 
7. Cardium. Animal tethys. Telia bivalvis fub- 
sequilatera, aequivalvis plerumque convexa, longitu- 
dinaliter collata, ftriata aut fulcata, margine dentata. 
Cardo dentibus mediisbinis alternatis : altero ut pluri- 
mum incurvo ; lateralibus remotis infertis. 
8. Mactra. Animal tethys. Telia bivalvis, in- 
aeq’uilatera, aequivalvis. Cardo dente medio complicate 
cum adje&a foveola, lateralibus remotis infertis. 
9. Donax. Animal tethys. Telia bivalvis, mar- 
gine fajpe crcnulato antico obtufiffimo. Cardo denti- 
bus duobus; rnarginalique folitario (rarius auplice, 
triplice, aut nullo) fubremoto fub ano. 
10. Venus. Animal tethys. Telia bivalvis ; la- 
biis margine antico incumbentibus. Cardo dentibus 
tribus, omnibus approximate lateralibus apice diver- 
gentibus. 
4. M. Animal an afcidia. Shell bivalve, generally 
gaping at one end. Hinge with broad, thick, itrong, 
teeth (feldom more than one), and not irfferted into 
the oppofite valve. 
5. S. Animal an afcidia. Shell bivalve, oblong, 
open at both ends. Hinge with a fubulate, refleCled 
tooth, often double, and not inferted in the oppofite 
valve ; the lateral margin more effaced. 
6. T. Animal a tethys. Shell bivalve, generally 
Hoping on one fide, in the fore part of one valve a 
convex, of the other a concave fold. Hinge ufually 
with three teeth ; the lateral ones in one ffiell being 
fmooth. 
7. C. Animal a tethys. Shell bivalve, nearly equi- 
lateral, aequivalve, generally convex, longitudinally 
ribbed, ftriated or grooved, with a toothed margin,, 
Hinge with two teeth near the beak, and a larger re- 
mote lateral one on each fide, each locking into the 
oppofite. 
8. M. Animal a tethys. Shell bivalve, of unequal 
fides, and aequivalve. Middle tooth of the hinge com- 
plicated, with a fmall hollow on each fide, lateral ones 
remote and inferted into each other. 
9. D. Animal a tethys. Shell bivalve, generally 
with a notched margin : the frontal margin very ob- 
tufe. Hinge with two teeth, and a fingle marginal one 
placed behind (rarely double, triple, or none). 
10. V. Animal a tethys. Shell bivalve; the fron- 
tal margin flattened with incumbent lips. Hinge with 
three teeth, all approximate ; the lateral ones divergent 
at the tip. 
11. Spondylus. 
