Fossils at Alexandra Dock , Belfast 
44 Praeger— 
Thracia convexa, W. Wood. 
Yery characteristic of the upper clay, in which it 
Common also with Lucinopsis in the shell layer 
clay. Quite absent from the lower and top clays. 
is found in abundance, 
which rests on the upper 
Corbula gibba, Olivi, 
Common in the upper clay, frequent in the lower bed. 
Mya arenaria, Linn. 
Top clays only, where it is in great abundance. 
Mya truncata, Linn. . , 
Plentiful throughout the upper clay, and very large. Single valves m the 
yellow sand. 
Fholas Candida. Linn. , 
With the two following species, this boring shell occurred only m the 
Pholad zone, between the upper and lower clay, where it was abundant. 
Pholas crispata, Linn. 
Perfect specimens, of most unusual dimensions (see p. 31), were observed 
all over the area of excavation, but only in the zone above-mentioned. 
* Pholas dactylus, Linn. 
A single complete specimen in the Pholad layer. 
Teredo ITorvegica, Speng. . 
Fragments of the calcareous tubes of this species were found in the upper 
clay. 
* Echinus sphsera, Mull. 
Spines of this large Echinoderm in the upper clay. 
Echinus miliaris, Leske. 
This “urchin ” is rather common in the clays, hut is of small size. ■ r. 
Stewart mentions a thickly -packed layer of the shells of this species near 
the surface of the upper clay at Spencer Basin.* 
JLmphidotus cordatus, Fenn. 
The fragile shells of this “ heart-urchin ” are rather common m the upper 
elay, and its spines occur in profusion. 
* Cancer pagurus, Leach. 
Fragments of a large claw in the yellow sand. 
* Carcinus maenas, Leach . 
I twice got remains of this crab in the upper clay. 
* Portunus depurator, Leach . 
Top clays, rare. 
Serpula triquetra, Linn. 
Yery frequent on shells all through. 
See Footnote, page 29. 
