448 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
5. Lamellibranchiata. 
Two new Hermaphrodite Lamellibranchs.* — M. P. Pelseneer justly 
directs attention to the rare condition of hermaphroditism exhibited by 
two Lamellibranchs. In some species of Pecten there is hermaphro- 
ditism, but one part of the gonad is male, and another female ; Pandora 
and Aspergillum have on each side two distinct gonads, one male and 
one female, and each with its own duct. In Lyonsiella there are two 
ovaries and two testes, and the same is the case with Poromya , though 
the arrangement of the ducts is different. 
It is remarkable that all the Lamellibranchs which have the sexes 
united belong to groups m which there is a good deal of specialization, 
such as the Pseudolamellibranchiata, the Eulamellibranchiata, and the 
Septibranchiata ; on the other hand, the more primitive forms are all 
dioecious. As this is true also of Gastropoda, we may conclude that in 
the ancestors of the Mollusca the separation of the sexes was the normal 
arrangement, and that hermaphroditism is a sign of specialization. 
Molluscoida. 
a. Tumcata. 
Anatomy of the Cynthiidse.t — Profs. H. de Lacaze-Duthiers and 
Yves Delage publish some preliminary notes on the anatomy and sys- 
tematic relations of the Cynthiidae. The pyloric gland is present in all 
members, whether there be a liver, as in the Cynthiineae, or no such 
definite organ, as in the Styelineae. The authors believe that the pyloric 
gland has a special digestive secretion, but with this an excretory function 
is possibly combined. They leave the last point to be worked out by 
Kowalevsky. The classification of Cynthiidae requires revision, and in 
distinguishing Cynthiineae from Stj 
laid on the alimentary system. 
The Cynthiineae have a distinct 
liver. The stomach is unswollen, 
without distinct limits, without 
marked internal projections, with- 
out a stomachal gutter, without 
an intestinal-pyloric ligament con- 
ducting the excretory duct of the 
pyloric gland, which opens directly 
on the wall of the digestive tube. 
The digestive loop is very large, 
extending almost to the level of 
the inhalent aperture ; it consists 
of two portions almost vertical and 
parallel throughout the greater part 
of their length. The species are 
always armed with spicules. The 
dorsal raphe bears languets, or a 
continuous lamella. 
Lineae the chief emphasis should be 
The Styelineae have no distinct 
liver. The stomach is swollen, 
definitely limited from oesophagus 
and intestine. It bears marked in- 
ternal projections, and a deep gutter 
ending in a cul-de-sac, in which 
the excretory canal of the pyloric 
gland opens, after following the 
course of the intestinal - pyloric 
ligament. The intestinal loop is 
almost transverse, and hardly 
extends above the level of the 
cloacal aperture. The species are 
usually unarmed, though sometimes 
slightly. The dorsal raphe always 
bears a simple continuous lamella. 
* Comptes Rendus, cx. (1890) pp. 1081-3. 
j- Arch. Zool. Exper. et Gen., vii. (1889) pp. 519-34 (1 pi.). 
