410 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Crustacea of Central Australia.* — Prof. Baldwin Spencer and 
Mr. T. S. Hall give an account of the Crustacea collected during the 
Horn scientific expedition to Central Australia. Living specimens of 
three forms only were obtained — Astacopsis bicarinata , Telphusa trains - 
versa , and Estheria packardi. 
The rate of growth of Apus and the Estheriidse must be very great. 
Certainly not more than two weeks after the fall of rain and probably 
only a few days, specimens of Apus measuring 2J to 3 in. in length were 
swarming about, and, as not a single one was to be found in the water- 
falls prior to the rain, these must have been developed from the egg. 
Estheria packardi may certainly, both in numbers and persistency, be 
regarded as the dominant species. It is worth noting that every species 
yields specimens of both males and females. So far as their habits are 
concerned, the Crustacea of this central district of Australia may be 
divided into two groups : firstly, those which can burrow and so tide 
over a certain length of dry season ( Astacopsis, Telphusa ) ; both species 
included in this group have a very wide distribution over Australia : 
secondly, those requiring that their eggs shall be dried up prior to 
development (Apus, Estheriidm) ; these are naturally well adapted to such 
a district, though none of the genera are by any means confined to it. 
American Lobster.f — Dr. F. H. Herrick, whose preliminary studies 
we have from time to time noticed, has prepared a complete monograph 
of the American lobster, making a study of its habits and development. 
Dealing with its distribution, he points out that this lobster ranges from 
the 35th to 52nd parallel, and may descend as far as 100 fathoms. It 
is most abundant and attains its greatest size in the northern part of its 
range. There is a great diversity in the characters of its environment, 
and this explains in some measure the many variations which occur in 
the habits of the animal, as in the time and frequency of moulting, in 
egg-laying, in the hatching of the young, and in the rate of growth. 
The lobster displays a considerable degree of intelligence, but Dr. 
Herrick doubts if the so-called auditory organs are real ears. Migrations 
appear to be due to the character of the coast and theAature of the bottom, 
and to be influenced by temperature and by the abundance of food. The 
best temperature appears to be about 55° F. ; a prolonged cold spell may 
prove fatal. When adult, the lobster is essentially a nocturnal animal, 
but the reverse is true in the larval period. It has developed to an 
extraordinary degree the habit of burrowing, and it almost always enters 
its burrow tail first. The lobsters feed upon fish, and even on smaller 
or weaker ones of their own kind. 
The law of the production of eggs may be expressed arithmetically 
as follows : — The numbers of eggs produced at each reproduction period 
vary in a geometrical series, while the lengths of the lobsters produc- 
ing these eggs vary in an arithmetical series. Tho largest number of 
eggs recorded for a single lobster is 97,440. The period of incubation 
is from 10 to 11 months, but it varies with the temperature of the water. 
The lobster does not spawn oftener than once in two years. A full 
account is given of the process of moulting. The rate of growth 
varies considerably with the individual and its surroundings. The 
* Horn Scientific Expedition) pt. ii. (1896) pp. 227-48 (4 pis.). 
f Bull. U.S. Fish Comm., 1895, pp. 1-252, pis. A-J and 1-54. 
