164 NEW-YORK FAUNA — MOLLUSCA. 
I refer to this species, a Chiton found in the harbor of New-York, attached to the ovaries 
of F. canaliculatus, and kindly placed at my disposal by Dr. Budd. It has a conspicuous 
series of holes on each side, between each valve, near their lateral margins; the lateral 
membrane appears to have been bordered with white. In other respects it agrees with the 
description given above. 
CuHITON APICULATUS. 
PLATE X. FIG. 201 and 202. 
Chiton apiculatus. Say, American Conchology, No. 8, fide Gould. 
€. pectinatus, GouLp. C. apiculatus, Ip. Invertebrata of Mass. p. 146, fig. 20: 
Description. Shell oblong-oval, convex: valves obtusely carinate, the central portion of the 
posterior margins becoming slightly beaked with age. Lateral areas triangular, studded with 
numerous rounded tubercles, disposed in no regular order, obsolete towards the apices, more 
numerous towards the lateral margins, which are rounded with an elevated marginal line. 
Medial areas lozenge-shaped, with numerous elevated rounded dots arranged in ten or twelve 
series on each side of the carina, parallel with the longitudinal axis of the body. In aged 
individuals, the lateral margins of the valves have the tubercles arranged in concentric lines ; 
terminal valves with concentric dotted lines ; margin membranaceous, obscurely granulate. 
Color, variable ; when freshly captured, greyish, inclining to ashen: in cabinets, they often 
appear bluish or ferruginous. ‘ 
Length, 0°5-1'0. Width, 0°3-0°6. 
I had indicated this species as C. jay, when Dr. Jay obligingly favored me with specimens 
precisely similar, labelled ‘‘pectinatus, Gould.” I therefore adopted the name, although I 
had not met with the description. More recently, the publication of the manuscripts of Mr. 
Jay has made us acquainted with the fact that he had described this species under the name 
which it bears at present. 
It is rather a common species, and is frequently found adhering to oysters. Like their 
congeners, they are parasitic, and, when detached, are capable of moving with considerable 
rapidity through the water. It has a wide range, having been found from South-Carolina 
nearly to Cape Cod in Massachusetts. 
(EXTRA-LIMITAL.) 
C. marginatus, Pennant. (Gowxp, Op. cit. 147, fig. 22.) Shell small, ovate, carinate and pointed 
behind: surface apparently smooth, but, under the lens, minutely shagreened in diamond-shaped 
granules. Color, dull ashen or greenish. Length, 0°5; width, 0-3. Wery rare. Seacoast of 
Massachusetts. 
