120 TEREDID^. 



Red Sea, India, Mauritius, Pacific Islands, Galapagos, Panama; 

 30 fathoms. Possil, 20 sp. Inf. Oolite — ; Europe, United 

 States. R. 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. 



E. 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 diA^erging necks. The siphonal orifices are rarely 

 four-lobed. 



SPENGLERIA, Tr3'on, 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. 

 H. rostrata, Speiigier (civ, 47). West Indies. 



CUCURBITULA, Grould, 1861. 



Distr. — C. cymbia, Spengl. (cv, 69). China. 



Shell regular, elongate, equivalve, gaping the whole length, 

 anteriorly enveloped 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, etc. 



Family TEREDID^. 



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, Europe. T. 

 navalis^ Linn, (civ, 48) ; L^. S. T. 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 



