Miscellaneous. 67 
the solitary specimen of the common form of Murex erinaceus my 
father recognized came, Purpura tetragona does not seem to have 
occurred. ; 
I may add that these shells, so abundant on Felixstow beach, are 
not specimens fallen from the Crag-cliff there, washed clean by the 
sea, but genuine recent shells. 
Tam, &c., 
Martlesham, near Woodbridge, Szartes V. Woop. 
June 16, 1883. 
Mediterranean Mollusca. 
In consequence of a suggestion made to me by the Rev. R. Boog 
Watson, that Brugnonia pulchella ‘Annals,’ 1883, xi. p.399)may be an 
embryonic form, I havere-examined my specimensand compared them 
with the young of various Gastropods. It is possible that the species 
which I described may be the fry of Cassis sulcosa, although I can- 
not satisfactorily determine this for want of young and fresh speci- 
mens of the latter species. If this surmise be confirmed by further 
comparison, Brugnonia must be consigned to the limbo of spurious 
genera, along with Sinusigera of D'Orbigny, Macgillivrayia ot 
Forbes, and several genera of O. G. Costa. 
J. Gwyn JEFFREYS. 
18th June, 1883. 
Further Observations on the Dimorphism of the Foraminifera. 
By MM. Monter-Cuarmas and SCHLUMBERGER. 
In a former communication on the dimorphism of the Foramini- 
fera we have indicated two existing types of Biloculine ; we will 
now show that the extinct species likewise participate in the two 
series of modifications that we have already noted in the existing 
species. ; 
Triloculina trigonula, d’Orb.—The form A possesses a very large 
central chamber (204 ,.) surrounded by three series of cells, the 
planes of symmetry of which form with each other angles of one 
third of a circumference. It will be remarked that the first serial 
chamber is compressed and corresponds to the canal of the Bilocu- 
line. The inrolment of the chambers from the first to the last 
remains the same, and follows three directions, passing through the 
planes of symmetry just mentioned. In this species the individuals 
of the form A often attain large dimensions. 
Triloculina trigonula, d@Orb.—The form B presents one of the 
smallest centralg chambers that we have met with; it is only 18 p. 
Around it are rouped five chambers, which reproduce the arrange- 
ment of the Quinqueloculine. This imrolment does not continue ; 
for, starting from the sixth, which becomes very embracing, the 
following chambers suddenly take on the Triloculine arrangement. 
Pentellina saxorum (dOrb.),—Middle Kocene, Parnes. This 
