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SUMMARY OF CURRENT RESEARCHES RELATING TO 
trude their eggs in June, July, and August, but at least ten per cent, 
lay eggs in other months of the year, and the process, though unusual, 
appears to be perfectly normal. Indeed it is possible that the like vari- 
ability would be found to obtain in the case of other animals with a 
fairly definite breeding season, if they were minutely studied. 
The law of production may be expressed thus : the numbers of eggs 
produced by female lobsters at each reproductive period vary in a geo- 
metrical series, while the lengths of the lobsters producing these eggs 
vary in an arithmetical series ; thus : 
Series of length : (in inches) 8 10 12 14 16 
„ eggs 5,000 10,000 20,000 40,000 80,000 
The eggs are carried, attached to the body of the female, for a period 
of from ten to eleven months ; it is probable that the survival of two out 
of every 10,000 larvae hatched is a high estimate. 
Conversion of Pagurinse into Lithodinse.* — M. E. L. Bouvier re- 
marks that though, at first sight, it is difficult to believe in the close 
relationship of Lithodes with the Hermit-Crabs, the researches of Boas 
have shown their affinities. Up till now, however, the mechanism of the 
change of the abdomen has not been exjdained, and it is his object to 
fill up this gap in our knowledge. He finds by a comparative research 
that the abdominal pieces of the Lithodinse, though similar in position 
to the corresponding pieces of the Pagurinae, have no real homology 
with them. To become typical Lithodinas a Eupagurus must first lose 
all its abdominal pieces, with the exception of those of the first and two 
last segments. The vast membranous surface of the abdomen is then 
invaded by calcified nodules, and it is by the fusion of these nodules 
that all the solid pieces, which characterize the representatives of this 
subfamily, are alone formed. 
Subterranean Crustacea of Hew Zealand-! — Dr. C. Chilton gives a 
detailed account of those interesting forms, to the existence of which he 
was the first to call attention, some eleven years since. This fauna is 
found to be peculiarly rich, and much more varied than that of either 
similar faunas in Europe or North America ; so far as at present known, 
it consists of three species of Amphipods, and three of Isopods, belonging 
to five genera. Of these Crangonyx is already known from the subter- 
ranean waters 'of Europe and North America ; one new genus, Cruregens, 
belongs to the Anthuridse, a family of which no members were previously 
known to inhabit underground waters, while another, Plireatoicus, is so 
peculiar that it must form the type of a new family of Isopoda. Its 
affinities are discussed at some length, and the reasons for regarding it as 
an Isopod and not as an Amphipod are clearly given ; on the whole, 
indeed, Plireatoicus is found to occupy a fairly central position among the 
Isopoda, as it retains to a greater extent than any other the typical charac- 
ters of the order. An amended account is given of Cruregens ; it is 
one of the Anthuridae, and, as it has only six pairs of legs, it appears to 
permanently retain what is ordinarily a larval character in Isepods ; it 
is recaarkable among the Anthuridae for having no palp to its mandible. 
Crangonyx compactus is remarkable for having only one ramus to the 
pleopoda, instead of the two which are almost universal in Amphipods. 
* Comptes Kendus, cxix. (1894) pp. 350-2. 
t Trans. Linn. Soc. Lond., vi. (1894) pp. 163-284 (8 pis.). 
