34 ACANTHOCHITES-NOTOPLAX. 



ish, stained here and there along the summit with black. Ligament 

 horny, furnished at the side of each valve with a small crest of 

 spicula. (Rve.) 



Cape Rivers (Belcher.) 



Chiton acutirostratus REEVE, Conch. Icon., t. 26, f. 137. July, 

 1847. Voy. Samarang, Moll., t. 15, f. 10. 



An elongated species of somewhat compressed growth, remarkably 

 distinguished by the sharply beaked structure of the umbones ; the 

 flat-grained sculpture of the valves approaches that of C. hirudini- 

 formis, to which it offers a singular contrast of color. (Reeve.) 



A. HEMPHILLI Pilsbry, n. sp. PI. 13, figs. 65, 66, 67. 



Elongated, the valves somewhat exceeding one-third the total 

 width in dried specimens. Valves rather elevated, carinated ; red, 

 more or less maculated with white. Girdle rust-brown. 



The intermediate valves are not beaked, being somewhat produced 

 backward on each side of the apex ; tegmentwn reduced to a heart- 

 shaped area by the encroachment of the girdle at the sutures, leaving 

 the valves in contact by only a small point at the ridge. The dorsal 

 band is very narrow, parallel sided, slightly elevated, and having a 

 few longitudinal striae. The latero-pleural or side areas are sculpt- 

 ured with fine flattened pustules, those on the posterior portion of 

 each valve being concave. Posterior valve elevated, the tegmentwn 

 small, somewhat pear-shaped, narrow in front, longer than wide, mucro 

 at about the posterior third. 



Interior light green at the sides, deep rose-red in the middle and at 

 the posterior margin of each valve. Sutural-plates light greenish, 

 the slits minute. Posterior valve not bilobed behind, having the usual 

 two slits, and between them a number (6-8) of smaller, irregular and 

 unequal slits or nicks ; posterior sinus obsolete. 



Girdle wide, rusty-brown, sparsely clothed with short microscopic 

 hyaline spicules, having a fringe of longer spicules at the periphery, 

 and 18 rather small tufts of whitish bristles. 



Length 24, breadth 11 mill. ; divergence about 115. 



Key West, Florida (Henry Hemphill.) 



This species is allied to A. rhodeus in the peculiarly narrow 

 dorsal band, the great encroachment of the girdle at the sutures, 

 etc. ; but it differs in the less developed side slits, the higher and 

 narrower tail valve and its peculiar multiple-slitting, and in other 

 features. It was collected by Mr. Hemphill at Key West. There 



