ANATOMY AND PHYSIOLOGY. 
Moll. 15 
and the outside in the foot of the Bivalves ; these are either macroscopic, 
as in the Unionidas and in Pecten , or microscopic, as in Gyclas [5p hcerium ] ; 
they may lie in the byssal furrow, as in Mytilus and Pinna , near the 
byssal glands, but are distinct from them, and the existence of these 
communications is proved, according to him, by injections without rents 
of the glands. Verh. Ges. Basel, vii., 29 pp. 
T. Barrois’s paper on the same subject [title, supra] has not been 
seen by the Recorder. L. Joliet also states, from observations made 
in the Heteropods, that the chief function of the renal sac is to expel the 
water which has been admixed with the blood; C.R. xcvii. pp. 1078-1081. 
Open communications (“ Poren-kanale ”) between the intercellular 
spaces within the skin and its outside are described in Helix pomatia and 
hortensis by A. Nalepa, SB. Ak. Wien, lxxxviii., Abth. 1, pp. 1180-1188, 
pi. ; abstract in J. R. Micr. Soc. (2) iv. p. 208. 
4 . Excretion and Secretion. 
Diffuse form of the renal organ observed in some Mollusks by S. Trin- 
Chese, Arch. Ital. Biol. iv. pp. 18-21. 
On the renal organs of Patella ; J. T. Cunningham, Q. J. Micr. Sci. 
xxiii. pp. 369-375. 
J. F. van B emm elen confirms the existence of renal orifices in the 
pericardium in Chiton marmoreus , C. niarginatus, and Chitonellus fasciatus , 
already stated by Sedgwick, but denied in other species by B. Haller; 
Zool. Anz. 1883, pp. 340-343. B. Haller maintains his statement that 
in Chiton siculus and fascicularis no such orifice exists ; l. c. pp. 
509-513. 
J. T. Cunningham describes the kidney of Aplysia. It is situated be- 
neath the shell, and has an external opening below the line of attachment 
of the gill, expanding and contracting in the living animal. Internally 
it is divided by flat trabeculae of connective tissue, and communicates 
with the pericardial cavity. It corresponds morphologically with the left 
renal organ of the Scutibranchia and Patella. MT. z. Stat. Neap. iv. 
pp. 420-428, pi. xxx. 
The renal organ of the oyster is described by J. A. Ryder, Bull. U. S. 
Fish. Comm. ii. pp. 345-347, and also incidentally by P. P. C. Hoek. It 
consists of numerous channels which not only extend to the surface of 
the body, but penetrate parts of the mantle ; its orifice is a lateral slit in 
the anterior and inferior part of the main part of the body, a little be- 
hind the genital orifice, which is situated in the same slit ; its cavity com- 
municates with that of the pericardium by the reno-pericardial channel, 
and the auricles of the heart have probably also an excretory function. 
Tijdschr. Nederl. Dierk. Yer. Suppl. i. pp. 54-74. 
Pedal gland, homologous to the byssal gland of the Bivalves, found by 
several Limnceidce and PaludinidcB\ P. B. Sarasin, Arb. z. Inst. 
Wiirzb. vi. pt. 2, pp. 105-108. 
The glands on the edge of the mantle or cover of the gills in Aplysia 
are described by F. Blociimann, Z. wiss. Zool. xxxviii. pp. 411-418, 
pi. xxii. 
1883. [vol. xx.] 
B 13 
