146 INVERTEBRATA OF MASSACHUSETTS. 



FAMILY PHYLLIDI^NJl, LAM. 



Shell not spii-cd, shield-shaped, composed of one or more pieces ; aperture 

 very large. 



GENUS CHITON, LIN. 



Shell oval, consisting of eight arched pieces, arranged across 

 the body of the animal in a series overlapping each other, their 

 ends set in the skin, which forms a rim around them. 



CHITON APICULATUS. 



Dorsal triangles with series of elevated points ; lateral triangles 

 with scattered, elevated dots. 



FIGURE 20. 



State Coll., No. 131. Soc. Cab., No. 740. 



Chiton apiculatus, SAY ; Amer. Conch., No. 8. 



Shell oval-oblong, convex, sub-carinated ; color grayish or 

 light-chestnut ; valves eight ; anterior valve crescentic, with three 

 or four concentric lines, and numerous, separate, elevated, equal, 

 sub-equidistant dots, arranged somewhat in regular lines along the 

 margin ; the six following valves have, on their dorsal triangles, 

 from twenty to thirty longitudinal series of elevated points, like 

 beads, somewhat converging towards the summit ; on the lateral 

 triangles, which are distinctly elevated above the dorsal triangles, 

 are scattered points like those on the anterior valve ; posterior 

 valve with the series of dots like the dorsal triangles, a central 

 tubercle, and the remainder with scattered dots like those on the 

 anterior valve. Margin coriaceous, with alternate stripes of white 

 and dusky pubescence. Length 1 inch, breadth f inch. 



Inhabits the southeastern waters of this State, after passing 

 Cape Cod. I have received it from Nantucket and Martha's 

 Vineyard. It is found more abundantly along the coast of New 

 York and New Jersey. Dr. Jay found it in great numbers at 

 Gardiner's Island. 



