270 



dense mass of minute granules or scales, and is banded white 

 and brown; it is also beset with three forms of spicules: (1) 

 bunches of coarse, horn-coloured, pointed spicules at the 

 sutures, placed similarly to those of an Acanthochiton, like 

 bunches of spicules, are scattered indiscriminately about the 

 girdle. (2) A fringe of lance-shaped white spicules, smaller 

 lance-shaped scales cover a good deal of the under side of the 

 girdle. (3) Long, slender, pale-brown spicules, surmounted 

 with lance-shaped heads of porcelain-white. These are dealt 

 with more particularly in the following paragraph. 



''Oar-headed Spicules.'' — These spicules, in the form 

 under description, differ from those of K. maUhewsi, Iredale^ 

 in that the ''heads," while porcelain-white and polished, 

 similar to that species, are different in shape, being smaller, 

 more slender, and tapering. They remind one more of a 

 stiletto than an oar-head. On the average these spicules 

 appear to be longer and proportionately more slender, though 

 this may be more apparent than real. 



These lance-shaped heads, mostly, seem equally rounded 

 on each side and straight, whereas those in the other species are 

 flat on one side and curved like the blade of ^a scull. Prac- 

 tically all the specimens taken in the D'Entrecasteaux 

 Channel, and most of those taken by Mr. May in Little 

 ITorf oik Bay, have these spicules present as well as the clusters 

 of coarse spicules and fringe spicules. The lance-headed 

 spicules are attached to the girdle either amongst the fringe 

 spicules or just above them. As we took great care with the 

 Channel specimens not to so clean off the vegetable growths 

 that cover them as to break off these spicules, we may conclude 

 that they are well preserved. A comparison with the South 

 Australian species, taken at Marino, reveals the fact that 

 the ''oar-headed" spicules are much less numerous in the Tas- 

 manian species than in the South Australian. The specimens 

 examined vary in length from 6 mm. to 36 mm., all sizes, 

 equally, having this feature present. 



Measurements. — As before stated, those examined vary 

 from 6 mm. to 36 mm., the latter being 21 mm. in width. 

 The smaller ones. are usually about three-quarters as wide as 

 long, giving a flattened, rounded appearance to the chiton. 

 In the type the median valve is 12 mm. from side to side, 

 anterior valve 8 mm., posterior valve under 6 mm. 



Radula is furnished with tri-lobed teeth, the central one 

 broader and slightly longer than the two lateral, but seems 

 slightly narrower than is the case in the South Australian 

 species. 



Hab.— Mr. W. L. May (to whom I am greatly in- 

 <iebted in connection with this investigation) and I found 



