Acanthochites.] AMPHINEURA. 31 



valve, enclosing a purple stripe or series of spots ; sometimes ashy- 

 whitish, faintly tinged with purple along the middle. Interior light 

 blue-green, fading on the sutural laminse ; anterior valve with 5 slits, 

 median valves with 1 slit ; posterior valve having a deep mopaloid 

 slit on each side, and about 4 shallower slits between ; the teeth ver- 

 tical, deeply grooved outside and lobed at the edge ; sinus deep, 

 angular. (Pilsbry.) 



Measurement of a large example : Length, 60 mm. ; breadth, 

 35 mm. A common size is Length, 35 mm. ; breadth, 23 mm. 

 Divergence, 130-140. 



Type, from Tasman Bay, in Mus. Hist. Nat., Paris. 



Hab. Bay of Islands, Hauraki Gulf, Great Barrier Island, Cook 

 Strait, Wellington Harbour, Cape Egmont, Dunedin, and Chatham 

 Islands. 



Remarks. There is a wide range of variation in colouring, angle 

 of divergence of the valves, and to a less extent in the contours of 

 the valves 



Maori. Etouani (fide Quoy and Gaimard). 



Genus 2. SPONGIOCHITON, Carpenter, 1873. 



Spongiochiton, Carpenter, "Table of Regular Chitons," 1873. Type and 

 only species : S. productus, Cpr. Spongiochiton, Dall, Proc. U.S. Nat. 

 is., 1882, 272, 283, 286, 289, 290 ; Man. Conch. (1), xiv, 26 ; xv, 7. 



Valves partly immersed ; insertion plates acute, ischnoid ; sinus 

 large, smooth ; mucro median, flat ; girdle spongy, produced for- 

 ward. (Cpr.) 



1. Spongiochiton productus, Pilsbry, 1892. 



Spongiochiton productus, Pilsbry, Man. Conch. (1), xiv, 26. 



Shell oval, the valves immersed two-fifths of their width ; exposed 

 portion rubicund, flat, the jugum arcuate, paler. Lateral areas 

 scarcely denned. Entire surface sculptured with prominent pebbles, 

 worn at the jugurn. Mucro submedian, flat. Interior : Posterior 

 valve with 6, central valve 1, anterior valve 5 slits ; teeth long, acute, 

 scarcely serrate ; sinus wide, smooth, extremely deep ; eaves narrow, 

 scarcely grooved. Girdle produced in front, spongy, sparsely covered 

 with chaffy scales and translucent hairlets. 



Length, 25 mm. ; breadth, 16^ mm. Divergence, 130. (Cpr.) 



Type in the British Museum (Cuming collection, No. 50). 



Hab. New Zealand. 



Remarks. I have not seen it. The species was described by Car- 

 penter in MS., and published by Pilsbry. 



