MOLLUSC A — CONCHIFERA. 
147 
Marion do Proc^, physician at Nantes, has made some observations 
on the motion of the Mytilus edulis, by means of its byssus. (Ann. 
des Sciences Nat. xviii, p. 59.) The author preserved an animal in a 
glass vessel, alive, for more than a month. It stretched its foot out of 
the shell, to a length of 30 centimeters, and fastened at the point the 
end of a byssus-thread to the glass. 
Mytilus niger, Benson ; Annals, ix. p. 489 ; testa oblonga, trigona ; 
cardine unidentato ; natibus subincurvatis, decorticatis, sub-epidermide 
albis, marginibus purpurascentibus ; intus margaritaceo-splendida, mar- 
gine purpureo : Chusan. 
Modiola Chenui, Recluz, Rev. Zool. 1842, p. 306 ; furrowed longitu- 
dinally, yellow, with a broad brown band in the middle ; hairy poste- 
riorly ; Brazil. 
M. elli-ptica, Lea (Sillim. Amer. Journ. xlii. p. 107), with purple spots, 
radiated stripes posteriorly and in front ; crenulated at the margin : 
Delaware Bay. M. pulex, id. ib. ; smooth, greenish with purple lines ; 
Do. M. senhousia, Benson, Ann. ix. p. 489 ; epidermide olivacea, 
obscure radiata ; ala natibusque strigis flexuosis spadiceis ornatis ; basi 
leviter emarginata : Chusan. M. cicercula, Moller, 1. c. p. 19 ; spherical ; 
rough ; green-yellow ; 2'". M. vitrea, Holb. in Moller (with Myt. 
decussatus, Mont.?) 
Dreissena purpurascens, Benson, Ann. ix. 489 ; t. oblonga sub-quad- 
rata, radiato-plicata, sub-epidermide albo purpureoque ornata; epidermide 
brunnea : Chusan. 
Cardium aquilinum, Mittre, Ann. des Sc. Nat. xviii. p. 191 ; testa 
minima, tumida, subcordata, gibba, obliqua, inmquilaterali, flavo-vires- 
cente, maculis rufo-fuscis et albidis ; costis planulatis, laevibus ; natibus 
prominulis, rufescentibus ; intus violacea; 6'": Toulon. C. elegantu- 
lum, Beck in Moller, 1. c. ; transversely oval ; white, with twenty or 
twenty-five fine tile roof-like ribs. 
Lucina cristata, Recluz, Rev. Zool. 1842, p. 270 ; t. ovato-subtri- 
gona, depresso -plana, valvula sinistra planissima, dextra vix convexa, 
albido-vitrea, pellucida, concentrice plicata ; plicis inferioribus striaefor- 
mibus, postice attenuata, angulata, margine superiore oblique recta, acute 
crenata, antice rotundata, superne tenue arcuatim emarginata ac cristata ; 
apicibus antice recurvis : Campeachy. 
Cyclas Steenhuchii, Moller, 1. c. ; unequal sides ; triangular ; blunt 
anteriorly ; bellied ; smooth ; greyish-yellow : Greenland. 
Cytherea effossa and excavata, Hanley, Proc. p. 123. Cyrena pur- 
purea, Lea (Sillim. Amer. Journ. xlii. p. 106; t. rotundato-triangulari, 
asquilaterali, subinflata, subcrassa, diaphana, et purpurea et alba, polita, 
striis transversis ; natibus prominentibus ; margine non crenulato : 
Delaware Bay. C. obesa, Hinds, Ann. x. p. 81 ; flavo-virente ; denti- 
bus lateralibus serrulatis ; intus pallide violacea ; Rivers, Feejee Islands. 
191 
