Callochiton.] AMPHINEURA. 15 



few fine growth-lines, otherwise smooth, the whole surface dotted 

 with small black eyes. Intermediate valves having the jugum sharply 

 rounded, central areas microscopically longitudinally closely striate, 

 4 to 5 deep grooves on each side, the innermost extending only over 

 half the length ; lateral areas distinctly raised, microscopically radially 

 striate, with numerous eyes, flatly and broadly nodulous by a few 

 concentric furrows, more pronounced near the margins ; sutures 

 crenate. Posterior valve smooth, with many eye-dots ; mucro in 

 front of the middle, low ; posterior slope slightly concave. Girdle 

 with elongated, pointed, and slightly keeled smooth scales. Colour 

 light fulvous, darker on the end valves and lateral areas ; girdle 

 white, with fulvous patches. Interior pinkish-white ; anterior valve 

 with 14, median valves with 2 slits on each side, and posterior valve 

 with 10 slits ; teeth blunt, propped up on the outside ; eaves spongy ; 

 the low and broadly rounded sutural lamime continuous across the 

 shallow sinus. 



Approximate dimensions : Length, 9 mm. ; breadth, 6 mm. 

 Divergence, 105. 



Type in my collection. 



Hab. Dusky Sound, 30 fathoms (R. Henry). 



Remarks. With regard to sculpture, this species stands between 

 C. empleurus and C. puniceus ; the former, however, has only deep 

 pits on the lateral areas, and the median valves with 4 slits ; the 

 latter has elevated longitudinal threads on the lateral areas, and the 

 median valves with 1 slit only. 



Fam. MOPALIIDJE, Pilsbry. 



Placipho roidea (part) and Mo^aloidea (part). Carpenter. Not Mopaliidce, 

 Dall. 



Chitons in which the valves are divided in the normal manner into 

 lateral and central areas ; the teeth of insertion are not pectinated ; 

 and the posterior valve has a posterior-median sinus, with 1 slit on each 

 side, or none. The girdle is more or less hairy, never scaly. Gill- 

 row as long as the foot. 



The normal number of slits in the anterior valve is 8 ; but this 

 is often increased or diminished by splitting or fusion of 1 or 2 teeth. 

 The slits correspond in position to external ribs. The intermediate 

 and posterior valves have not more than 1 well-developed slit on each 

 side, and even this is lacking in the tail valve of Plaxiphora. 



The girdle is frequently provided with pores at the sutures, each 

 pore generally bearing 2 or several bristles or hairs ; but the pre- 

 sence or absence of these pores is in no case of more than specific 

 value, and in some cases I have found it to be a mutable feature among 

 individuals of the same species. (Pilsbry.) 



