ANATOMY AND LIFE HISTORY OF MOLLUSCA. 177 



Nerita atrata, Reeve == JV. saturata, Hutton = JV. melanotragus, 

 E. A. Smith = N. punctata, Quoy, followed by Watson. (Voy. 

 "Challenger," XV., 13$.)* This shell appears to be equally 

 common on all the south coast of Australia, and on the south-east, 

 as far at least as Newcastle. It is a very hardy animal, as I can 

 testify that it bears change from salt to fresh water without 

 apparent injury ; but as a rule does not like water of any kind, 

 for it generally keeps out of it as much as possible. It has an 

 almost smooth black tegmentum with small white indistinct spots, 

 and is spirally grooved. On these grooves there are occasional 

 pits or depressions, and in these still more rarely there are minute 

 white eyes with a black dot or pupil in the centre. These are 

 easily seen with a somewhat powerful lens, because of the contrast 

 they make with the black tegmentum. But I have met so many 

 individuals in which there were no eyes, while in all they are of 

 such rarity and so easily destroyed, that I quite hesitate to 

 record them. On young shells, however, and near the margin of 

 the aperture in full-grown specimens, the tegmentum takes the 

 form of a much wrinkled periostraca, the wrinkles being parallel 

 with the aperture, and crossed at regular intervals with very fine 



*For some years past I have been accustomed to quote this shell under 

 Reeve's name, for which some explanation is necessary, and I cannot do 

 better than give here the words of Mr. Tryon in his " Manual of 

 Conchology. (Vol. x., p. 26, pi. viii., fig. 40.) "Reeve figured this 

 species for IV. atrata, Chemnitz— which it probably is not, and on this 

 account von Martens preferred for it the name N. punctata, Quoy — which 

 it certainly is not, whilst Hutton imposed the name of IV. saturata, and 

 E. A. Smith that of N. melanotragus, both in 1884 with a probable priority 

 of publication of the former name. Watson (Voy. " Challenger," XV., 

 132) reviews the whole subject, preferring the name IV. punctata. 

 Inasmuch as Chemnitz was not binomial, and therefore not entitled tO' 

 quotation, and his figures and descriptions are neither of them sufficient 

 for identification, whilst they indicate that at least two species were 

 confounded by him, I think it preferable to treat him as non-existent,, 

 and quote Reeve, especially as he has been followed by others so that 

 his atrata has become well known. JV. nigra, Gray (who quotes Quoy),. 

 in " Dieffenbach's New Zealand," has been cited by authors as applying 

 to the present species, but the name is not accepted by them on account 

 of the prior IV. nigra, Chemn. They show that Quoy never described a 

 IV. nigra, but then neither did Gray ; he merely mentioned the name in 

 his above list, and it is impossible to determine what species he may have 

 intended. Finally, different as this species is from IV. nigerrima, Chemn., 

 in its form and absence of columellar granulations — actually a group 

 distinction, I have nevertheless some suspicion that it is only a variety 

 of it, and that it connects that species with IV. morio, which, on account 

 of its smooth inner surface of the lip belongs still to another group. In 

 my saner moments, I am well aware that such vagaries of conjecture are 

 simply the demoralizing result of the questionable questioning which has 

 largely supplanted the questionless faith of the last generation of 

 conchologists." The only thing I have to add to this quotation is that 

 the columella of adult shells is slightly granular. 



L-July 4, 1888. 



