274 
ZOOLOGICAL LITERATURE. 
cylinder -axis is brought into immediate contaet with the 
contractile substance without mixing or becoming continuous 
with it. 
Dr. McIntosh, in a paper Trans. Linn. Soc.^ vol. xxiv. p.79)^ 
described, in 1863, the form and character of the hairs found on 
different parts of the common shore- crab. Upon the examina- 
tion of a great number of specimens, he found a wonderful 
sameness in the essential structure of the hairs in like situa- 
tions. While doubting whether the hairs, which we elsewhere 
have named auditory cilia, are endowed with any special sense, 
he yet considers them to be the most sensitive organs in 
the entire animal. While opposing the view that they are 
connected with the sense of hearing, he states, in a note, that 
otolithes or their homologues exist in the cavity at the base of 
the external antenna in Carcinus mcenas. In this the author is 
undoubtedly mistaken, as may be demonstrated by the excellent 
observations of Dr. Hensen on the organs of hearing in Crustacea, 
as well as by our own experience. 
The author notices but little the curious hairs armed with 
lateral curved spines that are attached to the branchial flabella, 
which probably fulfil the office, suggested to us by the late Prof. 
Quekett, of passing over the margins of the branchial plates, and 
so permitting the more ready access of water to the entire res- 
piratory surface. 
In 1863 Dr. V. Hensen published the result of very ex- 
tended researches upon the auditory organs of the Decapod 
Cnistacea Zeitschr. f. Wissensch. Zoologie,^ xiii. Bd., 3. Hft. 
1863), an abstract of which appeared in the February number 
(1864) of the ^ Archives des Sciences de Geneve,^ and also in 
the first volume of the fifth series of the ^Ann. des Sciences 
Naturelles.^ 
In this interesting memoir Dr. Hensen gives the details of his 
examination of these organs in twenty-eight different species of 
Decapoda. 
He first reviews the observations of previous authors, and ap- 
pears to have made himself acquainted with the writings of every 
carcinologist upon the subject, except those of Mr. Spence 
Bate, published in the Annals and Magazine of Nat. Hist.^ 
On the Homologies of the Carapace, and on the Structure 
and Function of the Antennte in Crustacea,^^ July 1855), and 
the Beport of the British Edriophthalma in the ^ Report of 
the British Association^ for 1858; in which are figm’ed, in the 
former, the auditory apparatus of the Brachyurous Crustacea, 
and in the latter, what the author considered to be the auditory 
cilia of the Amphipoda. 
Dr. Hensen next speaks of the otolitlies, and demonstrates 
that the sand found in the auditory chamber of the Prawns is 
