36 CH^TOPLEURA. 



in Southern specimens) ; carinated, the side-slopes nearly straight ; 

 central areas having beaded threads, lateral areas and end valves 

 having numerous scattered pustules. 



The lateral areas are distinctly defined, raised, and bear numer- 

 ous erect rounded pustules, irregularly scattered, not arranged in 

 rows. The end valves have the same sculpture, but the pustules 

 are more crowded. The central areas have minutely beaded longi- 

 tudinal threads, from 15 to 20 on each side. The umbo of the pos- 

 terior valve is in front of the middle, and rendered slightly pro- 

 jecting by the concavity of the slope back of it. 



The interior is white or stained with leaden in places. The 

 sutural plates are rounded ; sinus moderate but angular. Slits of 

 anterior valve 11, central valves 1, posterior valve 9-11. Teeth 

 slightly crenulated ; eaves short, solid. 



Girdle narrow, bearing sparsely scattered, transparent, short 

 hairs. 



Gills extending almost to the forward end of the foot, 24 branchiae 

 on each side. 



Length 17, breadth 10 mill. 



Length 16, breadth 12 mill. 



Cape Cod, Massachusetts, to Florida. 



Chiton apiculatus SAY, Amer. Conch., edit. Binney, p. 231. 

 SOWB., Conch. Illustr. f. 140. DEKAY, Moll. N. Y. p. 164, t. 10, f. 

 201, 202. GOULD, Invert, of Mass. (edit. Binney), p. 258, f. 522. 

 Chcetopleura apiculata Say, CPR. Ann. Mag. N. H. (4), xiii, p. 

 120. DALL, Proc. U. S. Nat. Mus. 1882, p. 410 ; Bull. 37, U. S. 

 Nat. Mus., p. 172, t. 51, f. 10. Chiton labeculatus REEVE, Conch. 

 Icon. t. 18, f. 108. 



The tubercles of the lateral areas and end valves of this species 

 show a lack of arrangement into radiating rows, which will readily 

 distinguish this from other species. 



It is quite commonly distributed along the Atlantic coast of the 

 United States from Naritucket to Florida, and has also been 

 reported from Haiti. 



The Northern examples are generally buff or ash colored, some- 

 times with patches of black ; but in a suite before me from Marco, 

 Florida, one specimen is scarlet and another purplish-pink. These 

 southern examples, whilst agreeing with the typical form in sculp- 

 ture, are smaller and comparatively narrower. (Figs. 78, 79.) 

 A specimen from Anglesea, New Jersey, has the lateral areas and 



