38 



EAST COAST MARINE SHELLS 



MODIOLOS MODIOLDS Linne. Horse Mussel. A 

 large coarse solid shell; epidermis deep 

 chestnut colorj groove for ligament deep; 

 animal dark orange or red. Length 4-6 

 inciies. Usually a deep water shell. 



PI. 11, Fig. 6 



Arctic Sea to Cape Hatteras, North 



Carolina 



MODIOLOS TDLIPDS Linn§. Tulip Mussel. 

 Shell smooth, bright yellowish or brown in 

 color with dark rays upon the posterior 

 portion; epidermis covered with scaly 

 growth and bristly hairs. Length 1.25 

 Inches. 



Possibly the handsomest representa- 

 tive of the family in this country. 



PI. 11, Fig. 7 



Cape Hatteras, North Carolina to 



West Indies 



MODIOLUS DEMISSUS Dillwyn. Shell somewhat 

 pinched toward center. Interior purplish 

 brown; otherwise similar to the following 

 subspecies. Length 2-3 inches. 

 Virginia to Florida 



MODIOLOS DEMISSOS PLICATOLA Lamarck. Hum- 

 ble Mussel. Shell brittle, with numerous 

 radiating ribs becoming fine upon anteri- 

 or portion; rather dingy; epidermis thin 

 and with a varnished-like surface, varie- 

 gated with yellow-green. Length 3 inches. 



Inhabits tide waters of small 

 streams, often imbedded in soil of banks 

 near high-water mark. 



PI. 12, Fig. 1 



Prince Edward Island to South 



Carolina 



MODIOLDS ABORESCENS Dillwyn. (M. papyria 

 Conrad). Paper Mussel. Shell cylindrical- 

 ly oblong, thin, smooth, sides rounded; 

 color yellowish white or green, portions 

 of surface more or less iridescent. Length 

 32 mm. 



PI. 12, Fig. 6 



Florida to Texas and West Indies 



MODIOLOS OPIFEX Say. Artist's Mussel. An 

 oval, reddish-brown shell; base contracted 

 behind center but not deeply so; between 

 this portion and the umbones the siirface 

 blackish and wrinkled; iridescent inside, 

 brilliant; edge crenulated. Length 13 mm. 

 PI. 11, Fig. 2 



North Carolina to the West Indies 



GENUS BOTULA Morch 1853 



BOTULA CASTANEA Say. Chestnut Mussel. 

 Hinge elevated; anterior margin rounded at 

 tip; posterior margin large; base with a 

 dilated but slightly impressed contraction 

 before center; epidermis wrinkled; bluish 

 inside. Length 15 mm. 



South Carolina to Florida; West 



Indies 



BOTULA FUSCA Gmelln (M. clnnamomea Lam.). 

 Dusky Mussel. Shell small, almost smooth, 

 inflated, epidermis dark brown; vunbones 

 high; hinge line curved. Length 10 mm. 



PI. 11, Fig. 4 



North Carolina to Florida; West 



Indies 



GENUS LITHOPHAGA Roeding 1798 

 (DATE SHELLS) 



Shell cylindrical, epidermis thick; 

 umbones low and near rounded anterior end; 

 posterior end wedge-shaped; hinge line 

 without teeth; ligament internal. They 

 are borers. 



LITHOPHAGA ANTILLARUM Orbigny (L. corru- 

 gata Phil.). Antillian Date. Shell 

 wedge-shaped when viewed from above; 'many 

 concentric furrows upon surface, particu- 

 larly near posterior end; base with fine 

 ribs fading out at anterior end; epidermis 

 a rich chestnut brown becoming almost black 

 In certain parts. Length 25-60 mm. 



PI. 12, Fig. 3 



Southern Florida and West Indies 



LITHOPHAGA NIGRA Orbigny (L. caribaea Phil.). 

 Black Date. Length 23 mm. 



PI. 12, Fig. 4 



South Carolina to Brazil. 



SECTION DIBERUS Dall 1898 



LITHOPHAGA BISULCATA Orbigny (L. appendlcu- 

 lata Phil.). Two-furrowed Date. A mostly 

 smooth and shining shell except for two 

 faint radiating sulcations, one above and 

 the other below the low rounded posterior 

 section; epidermis light chestnut color but 

 surface of shell usually covered with a 

 calcareous incrustation. Upon the latter 



