

i KM oi'HtjRA. 241 



ing 9, central valves 1 slit : the teeth deeply, el.xely pertinatrd out- 

 side. Posterior valve having the eaves projecting beyond the l.road, 

 flat crescent of callus which occupies the place of an insertion-plate. 



( Jirdle densely clothed with intermingled minute, larger and large 

 calcareous spines, (fig. 31.) 



New tiouth Wales (Wilkes) ; Port Jackson (Blainville, Coppinger 

 and Challenger Kxped. > Australia. 



Chiton incanns GOULD, Proc. Bost. Soc. Nat. Hist. 1846, ii, p. 145 ; 

 U. S. Expl. Exped., p. 315, t. 28, f. 432, 432a ; Otia, p. 6. Maugeria 

 invtnus GLD., Otia, p. 248. Acanthopleura incana E. A. SMITH, 

 Zool. Coll. H. M. S. ' Alert,' p. 81, 1884.? Chiton piceu* ANGAS, P. 

 Z. S. 1867, p. 223.Acanthopleura (/) incana (Old.) HADDON, 

 Challenger Polyplac., p. 25 (in part.) Chiton gaimardi BLAINV., 

 Diet. Sc. Nat. xxxvi, p. 546, (1825.) 



This species may readily be separated from all forms of Acantho- 

 pleura by the peculiar flat callus of the tail valve inside, altogether 

 lacking the pectination and slits which are present in Acanthopleura. 

 It differs also in having eyes scattered over the sides of the lateral 

 areas, and in having some of the girdle-spines striated. It differs 

 from the Japanese species in the differently colored interior and 

 sutural-plates, in the details of girdle-structure, etc. 



The spines on the white tracts of the girdle are unicolored whitish ; 

 on the dark tracts they are of a uniform black-brown color. Occa- 

 sional spines are striated like the scales of Ischnochiton. 



L. GEORGIANA Quoy and Gaimard. PI. 53, figs. 36-40. 



Body oval, thick ; girdle narrow, granulose, whitish with 8 white 

 stripes; valves arcuate, flattened, thickly striated ; brown, black in 

 the middle. 



The body is short, oval, much swollen ; girdle very thick, little 

 dilated at the sides, covered with very small rounded tubercles, white 

 with 8 black bands across each side. Foot narrow, yellowish. 

 Branchiae reaching to the buccal fringe, which is large. Valves 

 very wide, covering nearly the whole body, semicircular, but little 

 elevated, narrowed, somewhat heart-shaped, very thick ; having 

 concentric striae, the anterior and lateral most marked; of a deep 

 brown color at the sides, lighter in the middle with a black dorsal 

 line ; fourth and fifth valves equal and wider than the others. 

 Inside the valves are of a violaceous brown ; median valves with an 

 arcuate thickening. The sutural plates are short, rounded, separated 

 by a flat, straight median sinus. Insertion plates slit and crenulated. 

 16 



