288 A HISTORY OF RECENT CRUSTACEA 
long spines symmetrically arranged, while the preceding 
segment, which in the other species has some rather 
inconspicuous carine, here has about fifty-six long cylin- 
drical spines, ‘each of which ends in a blunt rounded tip 
with a perforation from which a soft tubular fleshy process 
protrudes.’ 
Leptosquilla, Miers, 1880, is defined as having the 
‘ophthalmic segment greatly elongated; rostrum not 
reaching beyond half the length of this segment,’ and to 
it is assigned the single species Leptosquilla Schmeltzu 
(A. Milne-Edwards), from the Samoa Islands. 
For a history of the development of the Stomatopoda 
the foundation was laid by Dr. Claus in 1871. Many 
additions have been made and much precision given to 
the knowledge of this subject by the researches of Pro- 
fessor Brooks. The transparent pelagic larve are fre- 
quently captured, and in consequence of their glass-like 
clearness the individual organisms can be easily studied, 
but there are special difficulties connected with tracing 
the series of changes which they pass through between 
the egg and the adult condition. Unlike most Malaco- 
straca, the Squillide do not carry their eggs about with 
them, but deposit them in their deep burrows, there to be 
aerated by the currents of water which the pleopods of the 
parent maintain. Hence the hatching of eggs in an 
aquarium has not yet been brought about. The older 
larvee are hardy, but seldom found near the shore. ‘The 
younger larvee can be found near the shore, bat seldom 
moult in confinement. The life-history has, therefore, to 
be traced by a comparison of numerous forms collected 
from the open sea, and here there is a twofold risk, of 
uniting the larve of quite distinct animals as stages in 
the life-history of a single species, and of disuniting the 
larval stages of a single species as though they belonged 
to distinct species or even distinct genera. In this laby- 
rinth the explorer has to be guided in part by general 
resemblances, but more especially by comparative measure- 
ments. Professor Brooks, having obtained a number of 
specimens which by general resemblance seemed to make 
