ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
705 
glossata. Dr. Haller proceeds to discuss the affinities of Oyprsea. As 
to the form of its shell it is clear that it is due not to spiral formation, 
for that is really very slight, but to the great development of the 
right-hand side of the anterior portion of the shell. This may be cor- 
related with the great elongation of the anterior part of the shell which 
lies above the gill-cavity. The increase in length leads to the elongation 
of the left auricle and the liver. The Cypraeidae are allied to the Taeuio- 
glossata by the characters of the radula, the separation of the pleural 
ganglia from the pedal cords and their fusion with the cerebral ganglia, 
the abbreviation of the enteric canal, the histological differentiation of 
the two lobes of the kidney, the development of a seminal groove and 
of a penis in the male, and, finally, the separation of the rectum from 
the ventricle. 
The author thinks the result of his investigations is to show that 
the Cypraeidae are very old forms of the Taenioglossata, which should 
be associated with the Rhipidoglossata ; they form, in other words, 
an intermediate link between these two great divisions of the Proso- 
branchiata. With the Paludinidse and Cyclophorus they form a group 
which may be called the Architasnioglossata. As there is a rudimentary 
right auricle in the Cypraeidae and perhaps also in their allies, the 
division of Monotocardia and Hiotocardia is shown to be out of con- 
sonance with the facts. 
Swammerdam’s Vesicle in Aplysia.* — Sig. G. F. Mazzarelli finds 
that the so-called vesicle of Swammerdam, which has been credited 
with many functions, from that of an ovary to that of a copulatory 
pouch, is connected, along with a seminal vesicle, to a duct which is the 
left portion of the divided hermaphrodite duct and opens near the vulva ; 
that it contains spermatozoa in varying abundance, and also ova in 
many cases, besides free spherules of lecithin, globules of fat, albumen- 
granules, and much liquid ; its function is that of purifying the sper- 
matic fluid from all extraneous matter. This is an important process in 
these Molluscs and it is probable that some doubtful structures in other 
Gastropods have a similar function. 
8 . Lamellibrancliiata. 
The Margin of the Mantle.j — Hr. B. Rawitz describes the margin 
of the mantle in Arcaceae, Mytilaceae, and Unionaceae. In Area it is 
divided into three folds : from the cleft between the internal and median 
folds the epicuticula is produced ; the median fold bears the eyes ; the 
cells of the outer fold pour forth a secretion utilized in forming the 
shell. The glands which are variously distributed on the margin are of 
two kinds, some forming mucin, others secreting a poisonous and pro- 
tective product. Rawitz describes the compound or conical eyes and 
the invaginate cups, and differs somewhat from both Carriere and 
Patten in regard to the details of their structure. As to the function 
of the former he grants that they are visual, and explains their abundance 
as the natural result of the loss of the head and of concentration on the 
only available position — the mantle-margin, where moreover their wide 
distribution is of use to a passive bivalve like Area , which cannot 
* Zool. Anzeig., xiii. (1890) pp. 391-9. 
t Jenaische Zeitschr. f. Naturwiss., xxiv. (1890) pp. 539-641 (4 pis.). 
