61 
weight. Part of the genus Modiola (Mytilus. 
Lin.), of the family of the Mytilacea, are con¬ 
tained in this compartment. 
Table 12. Modiolae continued ; and the ge¬ 
nera Mytilus (the muscle) and Pinna. 
Table 13. The family Malleacea, and part 
of the Pectenida; including under the former, 
the genera Crenatula (rather rare shells), Perna, 
Malleus (the two last classed as Oysters by Lin- 
neus), Avicula (Mytilus. Lin.), and Meleagrina. 
The Meleagrina margaritifera (Mytilus margari- 
tiferus. Lin.) affords valuable pearls, and the in¬ 
side is formed of the beautiful substance known 
by the name of Mother of Pearl. Under the 
Pectenida, are included the genera, Pedum, con¬ 
taining only one species, P. Spondyloideum, Os- 
trea spondyloidea, Gmel.), Lima, Plagiostoma 
(fossil), and Pecten, or Scallop shell. The Lima 
and Pecten were considered as Ostreae, by Lin- 
neus. 
Table 14. Pecten continued; and the 
genera Plicatula and Spondylus, or hinged 
Oyster. 
Table 15. Ostracea, including the genera, 
Gryphaea (only one recent species of this genus, 
G. angulata, is known); Ostrea, Vulsella, and 
Placuna. 
Table 16. Anomia, the last genus of the 
Ostracea. Also the families Rudista, and Bra- 
chiopoda. In the first, are the fossil genera 
Radiolites and Calceola, and the recent genus 
Crania; in the latter the genera Orbicula, Tere- 
bratula 
ROOM VIII. 
Nat. Hist. 
