GENERAL MORPHOLOGY. 
Crust. 9 
limbs present, all posterior to the first pair of maxillipeds 
biramous and locomotor ; six abdominal somites and a movable 
telson; the swimmerets present, but the other abdominal ap- 
pendages not. Ocellus and stalked eye present. Carapace with 
rostrum and two anterO-lateral spines; labrum with spine, body 
flattened vertically. 
4. The young Lucifer and the adult female have a long flagellum on 
the first antennae, a flagellum and scale on the second ; ear and 
antennary gland present ; neck elongated. The fourth periopod 
has disappeared, the others, as well as the maxillipeds, have 
lost their exopodites. All pleopods two-branched, except the 
first pair; tolson straight ; oxopodito of the swimmerets rounded. 
5. The adult male has a clasping organ on the first periopod, three 
rami on the second, two teeth on the lower edge of the sixth 
abdominal somite, a square end to the exopodite of the swim- 
meret, and a bent telson. 
The author further describes the development of an allied larva, belong- 
ing very probably to the genus Acetes , from the Zoea stage to the Schizo- 
pod form ; its last Zoea stage differs from that of Lucifer by a stalked 
eye, the two-jointed shaft of the first antenna, four rings in the endo- 
podite of the second antenna, two lobes in the metastoma, spiny somites 
and a deeply-forked telson; the Schizopod stage differs by the appendage 
of the 4 fourth thoracic segment being represented only by an exopodite, 
the exopodites of the periopods being covered by a cuticle, and function- 
less, and by the presence of three pairs of abdominal appendages beneath 
the swimmerets. Lucifer keeps all its Schizopod limbs for at least two 
more moults; A cetes Rioses its exopodites at once, and its maxillipeds, 
thoracic limbs, and antennae become like those of an adult Sergestid some 
time before the appearance of the five pairs of pleopods, and these do 
not appear together, but in two sets. The result of the process of de- 
velopment is nearly alike, but the paths followed diverge from each other, 
to converge again at the last stage. The author further compares the 
statements on the development of Sergestes , Euphciusia, and Penceus by 
Dohrn, Claus, F. Muller, and Metschnikoff with his own observations, and 
comes J-o the conclusions that^the Nauplius form is really most ancestral, 
that the Phyllopods andThe highest Brachyura are connected by a toler- 
ably complete series of ^intermediatejforms, and that this graduation con- 
sists of an increased dependence of the /various parts on each other, and 
increased prominence of the general individuality over the individuality 
of the somites or metameres. Phil. Tr. clxxiii. [1882] pp. 57-137, 
pis. i.-xi. ; previous abstract in P. R. Soc. xxxii. pp. 46-48. 
6. Moulting. 
F. Mocquard states that the arcades formed by mesophragms and the 
longitudinal branches connected with them are softened and finally 
broken in the moulting of the spiny lobster ; C.R. xcvi. pp. 204 & 205, 
also J. R. Micr. Soc. (2) iii. p. 211. 
Moulting of Limulua. [See infra, in the special part.] 
