24 



EAST COAST MARINE SHELLS 



light blue. Length 56 mm. 

 PI. 57, Fig. 2 

 Florida Keys; Texas; West Indies 



GENOS ACANTHOPLEDRA Gullding 1829 



ACANTHOPLEURA GRANOLATA Gmelin. Grained 

 Chiton. Shell oblong, surface usually- 

 eroded, dull; generally a patch of brown 

 on ridge of each valve; interior sea- 

 green, varying to lead blue, or on plates 

 fading to nearly white; girdle thick and 

 fleshy, covered with short little spines 

 which in turn are black or white and cal- 

 careous. Length 2.5 inches. The common 

 Chiton ^of the West Indies. 



PI. 56, Fig. g 



West Florida; Key Vacca; West 



Indies. 



Family Acanthochitidae 



GENUS ACANTHOCHITES Risso 1826 



Valves partially buried in, or 

 covered by, girdle; exposed part consist- 

 ing of a smooth or striated band; side 

 areas granulated but this feature some- 

 times lacking; five slits on anterior 

 valve, middle valves with one slit on each 

 side; posterior valve with two or more 

 slits. Girdle variable, ranging from 

 hairy to naked but always with four bris- 

 tle bearing pores around head valves and a 

 single series at sutures. 



ACANTHOCHITES FLORIDANDS Dall. Narrow and 

 long; black, purple-black or light brown 

 with white lined space at top of each 

 valve; valves entirely covered with excep- 

 tion of round dot at apex of first and a 

 narrow band along ridge of other seven 

 valves, band slightly swollen at apex of 

 each valve. 



Valves when separated are white, 

 pink, or purple; girdle wide, leathery and 

 naked, when fresh the color and texture of 

 a moist prune; each suture with minute 

 bristle-pore and four pores around head 

 valve, also with some short bristles upon 



each pore. 



This species is separable on ac- 

 count of the dark glistening girdle and 

 long white strokes along median line like 

 exclamation points without the dots. It 

 lives upon the reefs and is procurable at 

 low tide. Length 21 mm., breadth 7.5 mm. 

 (dried). 



PI. 57, Fig. 4 



Cape Florida; Key Largo; Key West; 



Tortugas, Florida 



ACANTHOCHITES HEMPHILLI Pilsbry. Elongated, 

 valves of dried examples exceeding one- 

 third of total width; valves elevated, 

 keeled, red and spotted with white; inte- 

 rior light green at sides, rose-red in 

 middle and at posterior end of each valve; 

 usually two slits in posterior valve to- 

 gether with six to eight unequal slits or 

 niches between; girdle rusty brown with 

 short microscopic spicules, fringed ones 

 at periphery and eighteen small tufts of 

 whitish bristles. Length 24 mm., breadth 

 11 mm. 



PI. 57, Fig. 16 



Key West, Florida 



ACANTHOCHITES PYGltAEUS Pilsbry. Allied to 

 A. splculus but much smaller and with a 

 high roof-like form, tufts also smaller. 

 Length 8 mm., breadth 4 mm. 



The smallest species of the genus, 

 often found in shallow water adhering to 

 bits of shell or on rock. 



PI. 57, Fig. 5 



Cedar Keys to Key West, Florida 



ACANTHOCHITES SPICOLOSUS ASTRIGER Reeve. 

 Shell oblong, depressed, not carinated; 

 valves of varying shades of green, often 

 touched with brown on sides, frequently 

 with wide white stripes on sides; interior 

 blue-green; notch deep and wide; girdle 

 velvety, green and with eighteen large 

 greenish-white tufts or spicules, the same 

 also on periphery. Length 20-22 mm., 

 breadth 9 mm. 



PI. 57, Fig. 3 



Florida Keys; West Indies 



