56 CRYPTOPLAX. 



Conch. Syst. ii, t. 135, f. 5 (only). — ? Chitonellus Icevis Lam. Not 

 Chitonellus oculahis Reeve, Conch. Icon., f. 7a, 7b. = (7. striatus. 



This species is peculiar in the circles of black and white bristles 

 surrounding the anterior valves. The well-defined dorsal smooth 

 areas, and the apparent lack of pores. These characters readily 

 separate it from C. larvceformis, a species otherwise rather similar. 

 It should be noted however, that some individuals of larvceformis 

 lack pores. 



C. LARV.EFORMis (Blainv.) Burrow. PI. 11, figs. 31-36, 40-43. 



Cylindrical and vermiform, wider posteriorly. Color pale buff, 

 clouded and maculated with reddish, and having two or several 

 transverse bands and a median dorsal line of the same ; the ventral 

 surface of a uniform pale tint, sejmrated from the lateral and dorsal 

 hitegwnent by a distinct line of longer white spicules. The first four 

 valves are in contact and eroded, the hinder four are widely separated, 

 the greatest space being between valves vi and vii. 



Anterior valve having the tegmentum about twice as long as the 

 anterior teeth, much eroded, the worn portion generally pink and 

 dull white (the pink sometimes replaced by olive) ; the unworn 

 outer rnn smooth except for growth-lines, and usually reddish. 

 Tegmentum of second valve somewhat pentagonal, broadest in front 

 of the middle, eroded. The other median valves are sagittate, the 

 posterior 3 or 4 being generally but little eroded, and showing a 

 sculpture of coarse, uneven longitudinal furrows, converging forward 

 toward a dorsal sulcus. Posterior valve (figs. 42, 43) having the 

 mucro produced far backward; cavity shallow. 



Interior of valves white, generally marked with pink in each 

 valve, but sometimes suffused with pale green. Anterior valve with 

 three slits, other valves having none. 



Girdle clothed with minute calcareous spicules, mostly red in color, 

 but white on the light patches; the spicules very short on the ante- 

 rior part of the body, with some longer ones intermingled, longer on 

 the posterior part (pi. 11, fig. 33). On the ventral surface the 

 spicules are extremely short and blunt ; and at the junction of base 

 and sides there is a crowded row of white spinelets (fig. 32). At each 

 suture there is a minute bunch of white spinelets (fig. 34), and 

 around the head-valve four such pore-bunches are found. In some 

 specimens some of the posterior pores are absent, and others lack all 

 pores. 



