190 M. E. L Bouvier on the Circulatory System 
tubes. The amalgamated Malpighian vessels exhibit no dila- 
tation near the opening of the intestine. 
The heart or dorsal vessel is constructed exactly as in S. 
tipuliformis . 
The respiratory system consists of two large respiratory 
tubes, placed at the sides of the abdomen, and composed of 
the united respiratory tubes which run from the trachese. 
These abdominal respiratory tubes are continued to the thorax, 
and subdivide. At the hinder end of the abdomen the two 
main respiratory tubes are united in a curve, but there is no 
connexion between them at any other part of their course, 
and thus they differ from the respiratory tubes of S. tipuli- 
formis , in which the conducting respiratory canals are con- 
nected by wide respiratory tubes at each segment. 
The male reproductive system is of the same form and 
construction as in S. tijpuliformis . It includes : — testes, con- 
tained in a common scrotum ; two deferent ducts, opening 
into the large round vesiculce seminales ; the ductus ejacula - 
torius , shaped like a long sinuous tube ; a horny penis, pro- 
vided with a furrow ; and two long, sinuous, accessory 
glands. 
The female reproductive system consists of the following 
parts: — (1) two ovaries, (2) two oviducts, (3) vagina, (4) 
copulatory pouch, (5) receptaculum seminis , (6) one unpaired 
accessory gland, (7) two paired accessory glands, and (8) 
ovipositor. Each ovary consists of four very long sinuous 
egg-tubes. These four tubes unite into one common oviduct, 
and then both oviducts open into the vagina. The receptac- 
ulum seminis is a little round sac, which opens at one end 
into the copulatory pouch and at the other into the vagina. 
The unpaired accessory gland resembles a long, narrow, 
sinuous tube, provided with two short, rounded, bag-like pro- 
cesses at the upper end. The paired accessory glands 
resemble two short sinuous tubes. The copulatory pouch is 
an oval and rather large sac, which opens outwards by a 
separate outlet through the deferent canal, but which com- 
municates with the receptaculum seminis by a connecting 
tube, and appears to be indirectly connected with the vagina. 
XXIV. — On the Circulatory System of the Carapace in the 
Decapod Crustacea . By E. L. Bouvier 
The circulatory system of the Decapod Crustacea, as described 
in the classic memoirs, after the investigations of Lund, 
* Translated from the ‘ Comptes Rendus des Seances de l’Academie 
des Sciences,’ tome ex., June 9, 1890, p. 1211 et seq. 
