OSTREA, ARCA, VENUS. 595 
BIVALVIA. 
See antea, p. 476. 
Ostrea sp. 
It is not improbable that Oysters are to be found in the mangrove-swamps both of 
the Hast and West Coasts of Central America, but I have hitherto failed to find any 
definite record concerning them. The West-Indian mangrove-oyster, known to me 
from Venezuela and Surinam, Jamaica, and Haiti, is O. arborea, Chemnitz, Syst. Conch.- 
Cab. vill. p. 46, t. 74. fig. 681 (copied in the French Encycl. Méth. t. 185. fiz. 1), 
v. Mart. in M. Weber's Zool. Ergebn. Reise Niederl. Ostindien, iv. p. 220 [=0O. para- 
sitica (Gmelin, part.), Hanley, ‘Recent Bivalve Shells,’ p. 298; and 0. rhizophorae, 
Guilding, Zool. Journ. iii. p. 542 (1828)]; it differs from the East-Indian 0. mytiloides, 
Lam., in the absence of the small knobs and pits at the edges of the shell near the 
hinge. The sharp-plaited 0. frons, L. (Mytilus), Chemnitz, loc. cit. viii. p. 61, t. 75. 
fig. 686; Hanley, Conch. Miscell. t. 2. fig. 5; Reeve, Conch. Icon. xviii. t. 19. fig. 41, 
is the West-Indian analogue of the East-Indian O. folium, L. 
On the West Coast O. columbiensis, Hanley, P. Z. S. 1845, p. 107; Conch. Miscell. 
t. 1. fig. 1; Reeve, Conch. Icon. xviii. t. 7. fig. 10, may perhaps live in the mangrove- 
swamps: see Morch, Malak. Blatt. vii. p. 211 (1860-61). 
Arca (Anomalocardia) tuberculosa. 
Arca tuberculosa, Sowerby, P. Z. 8. 1833, p. 19°; Philippi, Abbild. neuer Conch. i. p. 41, t. 1. 
fig. 2°; Hanley, Recent Bivalve Shells, p. 161°; Reeve, Conch. Icon. ii. t. 3. fig. 18°; 
C. B. Adams, Ann. Lyc. Nat. Hist. N. York, v. p. 687 (1852) °; Morch, Malak. Blatt. vii. 
p- 205 (1860-61)°; Kobelt, in Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Arca, p. 21, 
t. 6. fig. 847. 
Oval, swollen, equivalve, subauriculate, dark reddish-brown, with 36-37 radiating ribs, which are beset with 
scattered little tubercles, especially in the posterior part of the shell; ligamental area narrow. 
Long. 57-70, alt, 42-48, diam. 42 millim.; summits in 3 of the length. 
Hab. W. Nicaracta: Realejos, at low water, at the roots of the mangrove-trees 
(Cuming 4, Girsted "). 
S. Panama: Panama, in impalpable mud, under a mangrove-thicket, near high-water 
mark (C. B. Adams °). 
Venus (Cryptogramma) flexuosa, L. Sow. 
Rather dwarf specimens of this species, the largest 11 millim. in length, 7 in height, 
and 43 in diameter, summits in 3 of the length, posterior end much produced (as 
shown in Reeve’s Conch. Icon. xiv. t. 21. fig. 98 a), have been found by Herr Hoge at 
Progreso, Yucatan, with Potamides costatus. This species is widely distributed in the 
West Indies and along the coast of Brazil ; d’Orbigny, Voy. Am. mér. p. 553, mentions 
it even from the mouth of the Rio Plata. see 
