190 M. E. L Bouvier on the Circulatory System 



tubes. Tlie amalgamated Malpighian vessels exhibit no dila- 

 tation near the opening of the intestine. 



The heart or dorsal vessel is constructed exactly as in S. 

 iijndiformis. 



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 tracheae. 

 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 tlie respiratory tubes of S. tipuli- 

 formisj in which the conducting respn-atory 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. tijmliformis. It includes : — testes, con- 

 tained in a common scrotum ; two deferent ducts, opening 

 into the large round vesiculce seminales ; the ductus ejacula- 

 tortus, shaped like a long sinuous tube ; a horny penis, pro- 

 vided with a furrow ; and two long, sinuous, accessory 

 glands. 



Tlie female reproductive system consists of the following 

 parts: — (1) two ovaries, (2) two oviducts, (3) vagina, (4) 

 copulatory pouch, (5) receptacidum 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 unjmired 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 receptacidum 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. BouviEK *. 



The circulatory system of tlie Decapod Crustacea, as described 

 in the classic memoirs, after the investigations of Lund, 

 * Trnnsliited from the ' Comptos Roiulus ties Seauces do rAcadtJmie 

 dos Sfienees," tome ex., June 9, 18110, p. ll*ll ct scq. 



