CRYPTOPLAX. 53 



C. STRIATUS Lamarck. PI. 9, figs. 11, 12, 13, 14, 15; pi. 11, figs. 



37-39. 



Elongated, vermiform, very convex above, flat below ; hoary gray 

 maculated with rust-brown ; when dry, dull reddish-brown. The 

 valves are in contact with one another, or the posterior four may be 

 separated by short intervals, always much shorter than the valves. 



Anterior valve having the tegmentum longer than wide, more than 

 twice as long as the anterior teeth ; its surface cut into a coarse, 

 irregular granulation by peculiar zigzag impressions [very badly 

 rendered in pi. 9, fig. 11]. Median valves (fig. 13) sagittate, widest 

 at about the posterior third, tapering forward ; sculptured with 

 several deep, finely and irregularly zigzag grooves at the sides 

 (sometimes transformed into a pattern of v-shaped granules) ; the 

 dorsal area narrow, raised, smooth except for slight growth lines. 

 Posterior valve (fig. 14) like the median valves externally, but 

 having a short vertical granulose slope below the mucro. 



Interior light olive-green, generally becoming pink on the sutural- 

 laminse and teeth. Anterior valve having 3 slits, other valves 

 none ; posterior valve having the insertion-plate continuous, but 

 somewhat emarginate behind. 



Girdle wide, fleshy, densely covered with minute calcareous spine- 

 lets, and in most good specimens showing minute pores at some or 

 all of the sutures, and four around the head-valve. 



Length 55, breadth 12 mill, (average dry specimen.) 



Length 61, breadth 22 mill, (alcoholic specimen.) 



Chitonellus striatus LAM., An. s. Vert, vi, p. 317, 1819. DESH. in 

 Lam. vii, p. 481, 1836. SOWB., Genera of Shells 1. 139, f. 4; Conch. 

 Illustr., f. 62. BLAINV.,. Diet. Sc. Nat. xxxvi, p. 551, 1825. 

 REEVE, Conch. Syst. ii, t. 135, f. 1 ; Conch. Icon., f. 4. Chitonellus 

 gunnii RVE., Conch. Icon., f. 5, 1847. Ch. rostratus RVE., L c., f. 6. 

 Ch. oculatus RYE., 1. c., f. la, b (not of Q. & G.). Cryptoplax striata 

 +gunni-\-rostrata H. & A. ADAMS, Gen. Rec. Moll, i, p. 484. 

 ANGAS, P. Z. S. 1867, p. 224, 225. Chiton (Chitonellus] striatus 

 SMITH, Zool. Coll. 'Alert,' p. 84. Cryptoplax striatus HADDON, 

 Chall. Rep. xv, p. 39, t. 1, f. 9 ; t. 3, f. 9a-9m. 



Raines Island, Torres Straits (Reeve, for C. rostratus and C. 

 striatus), Port Lincoln (J. B. Harvey), Newcastle (Dr. Dieffenbach), 

 Port Jackson (Coppinger, Richardson, Jukes, King), Flinders 

 Island (J. Milligan) ; Tasmania (Reeve, C. gunnii) ; Tasmania 

 (Macgillivray and Gunn). 



