86 DISCOVERY REPORTS 



Genus Puncturella Lowe, 1827 

 Type (o.d.): Patella noachina Linn. 



The southern Puncturellas have long proved to be a stumbling block, and most authors have lumped 

 the southern records with the boreal noachina. Certainly on external shell characters there is no 

 marked difference between the northern noachina and the Antarctic-Subantarctic shells. 



Dall, however (1889a, pp. 356-7), revived falklandica A. Adams for shells from 449 fathoms, west 

 coast of Patagonia. He remarked concerning these Patagonian shells that they are ' amazingly like 

 P. noachina ; the only differences I have been able to see in the shells are that in P. noachina the fissure 

 is generally longer and less vertical, and the apex more posterior'. 



Dall did not examine the dentition of his southern shells, but I have found the radula of conica 

 (=falklandica) from St. 27, South Georgia, to show striking differences from the figures of the 

 Greenland noachina in Troschel & Thiele (1891, pi. 27, fig. 2). 



Allowing for differences in interpretation of these small radulae, especially difficult in the Rhipido- 

 glossa, owing to the numerous minute and crowded marginals and the large hooked outer lateral, 

 which assumes a different shape with the varying angles taken up in mounting, there is a marked 

 difference between the central and inner laterals in northern and southern examples. Since the central 

 and inner laterals always lie in one flat plane, and are easily seen, the differences noted between Troschel 

 & Thiele's figure and my slides demonstrate that in spite of similarity in the shells noachina can no 

 longer be applied to these southern shells. 



The difficulty, now, is to determine how many of the names that have been proposed for southern 

 shells represent valid species, and which of these names is applicable to the Discovery material. 



Rimula conica d'Orbigny (1841, p. 471) from the Falkland Islands is a juvenile of 4 mm. in length, 

 tall and strongly recurved at the apex. It can be matched exactly with young examples from the 

 Discovery material. 



Cemoriaprinceps Mighels ( 1841 , p. 42, pi. 4, fig. 9), type locality Maine, is a synonym of typical noachina. 



Puncturella cognata Gould (1852, p. 321, pi. 31, fig. 478), Orange Harbour, 16 fathoms, Patagonia, is 

 not so laterally compressed and has weaker sculpture than the Discovery material. 



P. analoga Martens (1903, p. 70, pi. 5, fig. 8), Kerguelen Island (length 8 mm., breadth 5 mm., 

 height 5 mm.), is sculptured with strong radials and can be matched with half-grown shells from the 

 Discovery material. Recorded from Macquarie Island by Hedley (1916, p. 37), and Tomlin (1948).* 



P. spirigera Thiele (19 12). Evidently a distinct species with regular ribs separated by linear grooves ; 

 a tall shell with strongly recurved apex. 



Puncturella conica (d'Orbigny) 



Rimula conica d'Orbigny, 1841, p. 471. 



Cemoria falklandica A. Adams, 1862, p. 208, fig. 14. 



Puncturella noachina Watson, 1886, p. 42. 



Puncturella falklandica Dall, 1889 a, p. 356. 



Puncturella falklandica Pilsbry,i890, p. 231, pi. 63, fig. 33. 



Puncturella analoga Martens, 1903, p. 70, pi. 5, fig. 8. 



Puncturella noachina Strebel, 1907, pi. 2, figs, z^a-c, z$a-d. 



Puncturella noachina Strebel, 1908, p. 79. 



Puncturella noachina Thiele, 191 2, p. 234. 



Puncturella noachina { = i falklandiana , sic): Melvill & Standen, 1912, p. 344. 

 * Since the above was written I have examined this B.A.N.Z.A.R.E. material consisting of fifty-one specimens, and find 

 that they are constant in having very weakly developed radials. These Macquarie Island shells are probably neither conica nor 

 analoga, but topotypes of the latter are required to determine this. 



