206 



Base not flat, sides concave : so that the shell rests on its 

 ends : subcircular : margin simple. Apex pinkish, ground 

 colour faint brownish pink. From just below the pink aj^ex 

 radiate four broad opaque white bands, which increase to 

 eight. 



Dim. — Height, 2o mm. : major diam., 2'7 mm. : minor 

 diam., 2*25 mm. 



Hah. — Spencer Guif, dredged alive, depth unknown, 7 

 individuals. 



The radula contains about 36 consecutive segments, each 

 consisting of two marginals, two outer laterals, and one inner 

 lateral. 2(2'rO'l'2)2. The marginals are thin and colour- 

 less, with a long stem (fig. 8), the extremity expanded later- 

 ally in a central direction (fig. 11), and reflected (fig. 10) ; 

 the outer one the larger and including the inner (fig. 11). 

 The outer laterals are short, stout, very closely approximated, 

 booked at the end, and brown (figs. 8, 11, 14). The inner 

 laterals are less approximate, much longer (figs. 8, 11, 13), 

 articulate at their base with the outer laterals (figs. 9, 12), 

 but are separable from them. 



Ohs. — I have called it a Helcioniscus. The dentition 

 does not correspond with that of any of the Patellidtie^, which 

 seem all to have three marginals, whereas this appears to have 

 only two. But for this its dentition is that of Helcioniscus, 

 3(2'] •0*1*2)3. and Patellina; but its branchial cordon is in- 

 complete, and this would place it in Helcioniscus. 



The figures are not all drawn from the same radula, but 

 from three radulse obtained from three individuals of appar- 

 ently the same species. 



Patella ustulata, Reeve. 



Fatr.lld ustulaid, Rve., Couch. Icon., 1855, vol. viii., pi. xxxi., 

 f. 88, a, h; Ten. -Woods, P.R.S., Tasiii., 1877 for 1876, p. 49; also 

 1878 for 1877, p. 45; Tate and May, Proc. Linn. Soo., N.S.W., 

 1901, vol. 26, pt. 3, p. 411; Pritchard and Gatliff, Proc. Roy. See, 

 Vict., 1903, vol. XV. (n. s.), p. 193: P. (scufrJlastraJ vsUilafciy 

 Rve., Pilsbrv., in Tryon's Man. Condi., vol. xiii., p. 101, pi. xxii., 

 figs. 11, 12." 



Pniella tasmnnica, Ten. -Woods, Proc. Royal Soc., Tasm., 1876 

 for 1875, p. 157; also 1877 for 1876, p. 49: 1878 for 1877, p. 45; 

 Tate and Mav, op. cit.. p. 411; Pritchard :ind Gatliff, op. nt., 

 p. 193. 



This species is not found in Adcock's Handlist, and was 

 only represented by a few poor specimens among our col- 

 lectors until recognized by me at Port MacDonnell in Janu- 

 ary of this year, when very many somewhat beach-worn 

 specimens were found. 



