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. 

 tipuJiformis. 



The respiratory system consists of two large respii-atory 

 tubes, placed at the sides of the abdomen, and composed of 

 the united respiratory tubes wliich run from the trachea3. 

 These abdominal respiratory tubes are continued to tlie tliorax, 

 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. tipuU- 

 formisj 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 aS'. tipuliformis. 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) receptacidum semims, (6) one mrpaired 

 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 recej^tac- 

 ulum seminis is a little round sac, which opens at one end 

 into the copulatory pouch and at the otlier 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 ratlier 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 Seauces de I'Academie 

 des Sciences,' tome ex., June 9, 1890, p. 1211 et seq. 



