24i LORD HOWE ISLAND. 



The Littorinidte are another strongly tleveloped family. The widely 

 distributed Littorina Jiemenensis, var. mauritiana, is found wherever there 

 are rocks along or above high-water mark. Both the black basaltic rocks 

 and the coral-sand rock, where forming reefs and ledges, are frequented by 

 this shell, which appears to be equally indifferent whether it is lapped gently 

 by the incoming tide, or remains high and dry some feet above flood water- 

 mark, and dependant only on spray. It is a remarkable fact that it may 

 be found covering the rocks at some points, in large numbers, whilst, 

 without the slightest indication why, many square feet of similar rock in a 

 like position, are almost deserted by it, and its place taken either by a 

 Patella or Nerita. In a similar dry position the writer obtained several 

 examples of Littorina nodulosa on the basaltic spurs running out from 

 the north extremity of Ned's Beach, but the shell does not appear to be by 

 any means common. Still rarer than this species is L. ^^licata, Linn., 

 obtained on the blocks of basaltic rock strewn on the ledges to the south of 

 Ned's Beach, but in this case always between tide marks, and fully covered 

 at high water. Of the rarer forms of Littorina, L. undulata, Gray, was also 

 collected. 



The Neritida^ are an equally interesting group of shells, both from their 

 prevalence and general distribution. Nerita melanotragiis, E. A. Smith, 

 occurs in thousands everywhere, hut more particularly at those points where 

 the beach, between tides is composed of the coral-sand rock forming the 

 low-lying portions of the Island. On the off-lying islets, especially l^abbit 

 Island, and along the east coast generally this species is decidedly smaller, 

 than when found on the rocky ledges between the landing place and 

 the Old Settlement, where some fine specimens can be obtained. L. 

 melanotragus is found plentifully on the coast of New South Wales, and also 

 at Norfolk Island. Another common form is Nerita antiquata, Eecluz, a 

 shell found on the Victorian coast, but rare here. On the south shore end of 

 the Coral-reef the most typical shell is Turho imperialism Linn., with its won- 

 derfully massive operculum. Notwithstanding its frequency, however, it is 

 diificult to obtain cabinet specimens, the shell appearing to have a natural 

 affinity for the growth of an incrusting nullipore, and other epiphytic 

 organisms. Associated with T. imperialism although in less numbers, we found 

 Purpura siiccincta already mentioned, and numerous examples of Dolium 

 varicgatumm Lamk. An immense specimen of this shell was brought from 

 Lord How^e, by the Visiting Magistrate, Mr. H. T. Wilkinson, and ex- 

 hibited at the Liuuean Society, Sydney,* measuring about nine inches in 

 its longest diameter, by a transverse measurement of eight inches. At the 

 meeting in question, Mr. Brazier stated that the species had not previously 

 been found so far east of the mainland of Avistralia. 



Only two species of Trochus \\eve found, one, T. Torresi, and another 

 known to Mr. Brazier only, from Western Australia. The place of Trochus 

 is taken by the little trochoid Micella plicatula, Phil., another Norfolk 

 Island shell. It seems to love crawling over small stones, on a more or less 

 flat beach, especially if of a muddy nature. Such patches are to be found 

 on a part of the foreshore of the Old Settlement, and around Eabbit Island, 

 where it is very plentiful. A small form of Ilaliotis is plentiful on the 

 Coral-reef, the largest examples averaging about one inch in diameter. We 

 did not observe any of the larger species of this genus. Although found on 

 the Coral-reef it cannot be said that Patella is common there, but here and 

 there along the coast line P. framoserica, Martin, becomes more so ; whilst 



* Proc. Linn. Soc. N. S. Wales, 1885, x, p. G96. 



