120 TEREDIDA. 
Red Sea, India, Mauritius, Pacific Islands, Galapagos, Panama ; 
30 fathoms. Fossil, 20 sp. Inf. Oolite—; Europe, United 
States. &. hians, Chemn. (civ, 46). W. Indies. 
Shell regular, wedge-shaped, umbones anterior; gaping widely 
in front, close behind; ligament narrow, external; pallial sinus 
deep; tube irregular. 
Animal with mantle closed, and thickened in front ; foot finger- 
like, grooved, sometimes byssiferous; siphons long, separate 
only at their extremities; lips simple, palpi sickle-shaped, gills 
unequal, prolonged freely into the branchial siphon. 
R. modiolina perforates shells and limestone; its holes are 
regular, about two inches deep and a half inch diameter; the 
external orifice is hour-glass shaped, and lined with a shelly 
layer which projects slightly. When burrowing in oyster-shells 
it often passes quite through into the ground below, and then 
completes its abode by cementing such loose material as it finds 
into a flask-shaped case, having its neck fixed in the oyster-shell ; 
in some fossil species the siphons were more separated, and the 
flasks have two diverging necks, The siphonal orifices are rarely 
four-lobed. 
SPENGLERIA, Tryon, 1861. Valves elongate-cuneiform, trun- 
cated at the posterior end, with an elevated, transversely lamel- 
lated portion radiating from the beaks to the posterior margin. 
R. rostrata, Spengler (civ, 47). West Indies. 
CucuRBITULA, Gould, 1861. 
Distr.—C. cymbia, Spengl. (cv, 69). China. 
Shell regular, elongate, equivalve, gaping the whole length, 
anteriorly eny eloped by the mantle of the animal. 
Tube very short, ovate or gourd-shaped, composed of succes- 
sive calcareous layers or cups involving bits of shell or sand. 
Attached by one side to shells, ete. 
Famity TEREDID A. 
Animal vermiform, its two long siphons furnished at their 
extremity with each a testaceous pallet; valves gaping, with an 
interior spoon-shaped process proceeding from the hinge. 
Animal and valves contained within an irregular calcareous 
tube, with which it lines its perforations in timber and clay. 
TEREDO, Linn., 1757. 
Distr.—21 sp. Norway, Britain, Black Sea, Tropics, 119 
fathoms. Fossil, 24 sp. Lias—; United States, Kurope. T. 
navalis, Linn. (civ, 48); U.S. 7. Norvegica, Spengler (cv, 
70-73). 
Shell globular, open in front and behind, lodged at the inner 
extremity of a burrow partly or entirely lined with shell; valves 
