ANATOMY AND riTYSIOLOGY. 
MolL 11 
not primitively a membranous plate, but a row of filaments which 
can bo united by coalescence. Q. J. Micr. Sci. (2) xvii. pp. 43-GG, 
pis. iv.-vii. 
Peculiar membranaceous fringe-shaped organs on the sides of the trunk 
between the mantle and the basis of the gill in Mytilus edulis, are de- 
scribed by A. Sabatier as “ organes godronnes they contain certain 
large cells filled with blood, and are probably to be regarded as acces- 
sorial respiratory organs. Ann. Sci. Nat. v. No. 1. H. v. Ihering 
thinks them to be identical with what he has called “ epipodial gills ” in 
Patella and Chiton. SB. Soc. Erlang, ix. p. 136, and JB. Anat. Physiol, 
vi. p. 116. 
The so-called organ of Bojanus in Bivalves is the subject of an elaborate 
paper by H. A. Griesbach ; after having mentioned the results of the 
work of former anatomists with regard to it, he gives a minute descrip- 
tion. It consists of two pairs of twisted holes, a superior or exterior 
(Yorhohle, entry or fore-court) and an inferior; the superior with plain, 
the inferior with plaited walls. The two superiors have a common orifice 
outside ; the inferiors open into the superior of the same side. The 
framework of the whole is formed by conjunctive membranes, without 
muscles ; it receives blood through several clefts from the median venous 
sinus, not from the pericardium. Its function is probably only excre- 
tory, of renal nature, and it is very improbable that water from without 
is received by the common orifice. The author compares it with the 
renal organs of the other classes of Mollusca^ and even with the so-called 
segmental organs of the Annelides. Arch. f. Nat. xliii. pp. 63-107, 
pis. vi. & vii. 
With regard to the Opisthohranchia^ H. v. Ihering also supports the 
view that by the communication of the renal organ with the pericardial 
cavity, water from outside is received, not for being intermingled as a 
whole with the blood, but only for respiratory purposes, some plaits at 
the inside of the pericardial sac acting as “ pericardial gills.” Z. wiss. 
Zool. xxix. p. 600. 
The same author, in a subsequent paper, adduces new proofs in favour 
of this opinion, stating that in the Patellidce and Bhipidoglossa, which 
are the lowest divisions of his ArthrocochlideSf the kidney is double and 
quite homologous with the so-called organ of Bojanus in the Lamelli- 
branches, the left one becoming rudimentary ; in the Fissurellidce and 
Patellidce^ the orifice of the genital organs even being situated within 
this organ, as in some Lamellibranches. Z. wiss. Zool. xxix. pp. 583-614, 
pi. XXXV. The same abbreviated in Ber. Yers. Naturf. Munich, 1877, 
p. 170. [The remarkable anatomical resemblances between the Rhipido- 
glossa and the Bivalves have long ago been urged by Cuvier, Quoy & 
Gaimard, and 0. A. Morch.] 
C. Semper opposes [as does Simroth ; see Zool. Roc. xiii. Moll. p. 6] 
Ihering’s theory, that the pulmonary cavity of the Stylommatophora is 
morphologically homologous with the kidney of the branchiate Mollusca ; 
Arb. Inst. Wurzb. iii. pp. 480-488. Ihering maintains his views, assign- 
ing to Peronia and Veronicellus the lowest place among his Nephro- 
pnensta ; SB. Soc. Erlang, ix. pp. 131-168. 
