ANA.TOMY AND PHYSIOLOGY. 
Grust. 8 
The development of Palcemonetes vulgaris (Say) described by W. 
Faxon ; it undergoes a full metamorphosis, issuing from the egg in the 
Zoea-ioxm, i. e., provided with a pair of compound eyes, two pairs of 
antennae, two pairs of maxillae, and three pairs of swimming feet, the 
future maxillipeds, without gills, abdomen wholly devoid of appendages, 
and telson not clearly marked off from the sixth abdominal segment. 
The thoracic legs are subsequently unfolded in succession, beginning with 
the front, only the last pair are earlier than the penultimate ; all except 
the last furnished with external natatory branches, which are reduced by 
subsequent moults, and finally disappear altogether. During the evolu- 
tion of the thoracic limbs, the abdominal appendages make their appear- 
ance ; first the posterior pair, which develop within the telson, then the 
anterior pairs. Each successive stage has been actually reared in con- 
finement from its predecessor, with one exception. The eggs of the 
freshwater species, P. exilipes (Stimps ), are much larger in size and 
fewer in number. Bull. Mus. C. Z. v. No. 15, pp. 303-330, with 4 pis. 
Larva of Thysanopoda norvegica (Sars) described by Smith, Tr. Conn. 
Ac. V. p. 91. 
The larval stages of Squilla empusa (Say) are described by W. E. 
Brooks, Chesapeake Zool. Laborat. 1878, pp. 143-170, pis. xviii.-xxi. 
The development of the embryo of Cymothoa (vstroides and parallela 
(M. E.), from the first cleaving of the egg, is described and compared 
with that of other Crustacea by J. F. Bullar, Phil. Tr. clxix. pp. 505-521, 
pis. xlv.-xlvii. 
C. Grobben describes the development of Moina rectirosfris (Baird), 
which progresses from the embryo to the full-grown animal in two days 
and a half, and adds several theoretical considerations concerning the egg 
and germinal layers in various Arthropoda, the embryonal forms called 
Nauplias and Trochophora^ the very early appearance of the genital 
organs in Moina as well as in Aphis and Miastor, parthenogenesis, 
sporogony, and heterogony, &c. Arb. z. Inst. Wien, ii. No. 5, pp. 1-51, 
pis. i.-v. 
7 . General Biology. 
Note on sounds emitted by some Crustacea^ G. Brown Goode, 
P. U. S. Nat. Mus. 1878, pp. 7 & 8. 
P. Mayer has observed that several species of Idothea change colour 
according to surrounding objects within half an hour, but never if both 
eyes have been extirpated. MT. z. Stat. Neap. i. pp. 520 & 521. 
[Similar observations on Nica; Zool. Rec. xv. Crust, p, 10.] 
Cave Fauna. See Gammarus p>uteanus, Asellus cavaticus, and Cantho- 
camptus cavernarum (sp. n., Packard). 
Richet records his experiments on the influence of heat upon the life- 
actions of the crayfish. At 23-24^^ the pincers are only feebly moved 
when touched, at 24 -26'^ there is complete loss of voluntary nervous 
action, at 27-29° reflex action disappears, at 28-30° the respiratory 
movements are affected, and temperatures higher than 32° are mortal. 
C. R. Ixxxviii. p. 977 ; abstract in J. R. Micr. Soc. ii, pp. 714 & 716. 
