KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:o (6. | 
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A. Marine Mollusca. 
1. Mollusea from the shores of Broome. 
Pinna bicolor CHEMNITZ, var. Å great many specimens of this species were 
taken on the muddy shores of Broome, the largest one measuring 22 cm in length. 
The colouration, consisting of dark radiating stripes, corresponds to that of the typical 
P. bicolor (figured by REEvE, Conch. Icon. 11, fig. 17) but the shape differs in its 
straighter, obtusely truncated and not slowly curving posterior margin. "The specim- 
ens are like some from Madagascar collected by Dr. KAUDERN; an especially char- 
acteristic feature are the sinuous squamular scars, which give the longitudinal ribs 
an imbricate appearance. ”Traces thereof, together with distinct squames, are present 
in the typical P. bicolor, judging from specimens in the Swedish State Museum. 
The Australian form is only somewhat darker than that from Madagascar and shows 
confluent rays, especially on the inner shell surface; at the posterior margin there 
is, however, a lighter zone, where they appear clearly. 
P. nigra CHEMNITZ, 1 shell of 29 cm, interiorly dark brown with the mu- 
scular scar causing a curving-out of the pallial line, exteriorly with obscure broad 
longitudinal ridges, with dense squamular scars. 
P. chemnitzi HANLEY, 1 sh., 1. 206 mm. 
Ostrea hyotis LINNE, 1 sh., diam. (breadth) 17 em. 
0. imbricata LAMARCK, 1 sh., diam. (breadth) 12 cm. 
On these Ostrea shells there were attached several mollusca, such as Septifer, 
Chama, Sigaretus. 
0. inermis SOWERBY, some worn shells, max. 1. 62 mm. 
0. ordensis SAVILLE-KENT. Broome, on twigs of White Mangrove (Avi- 
cennia officinalis), many sps, max. 1. about 15 mm. This small-sized form was 
discovered by SAVILLE-KENT in Cambridge Gulf and briefly mentioned by him in 
1889 (Proc. Roy. Soc. Queensland, 6, p. 224—5). He described it in 1891 and later 
