112 E. A. Andrews — Anatomy of the Spider Crab. 



marking oft'tlie anterior portion {i), which is without cliitinous lining, 

 from the posterior, straight portion {i') which is tlius lined. The 

 anterior portion receives the secretion of a pair of cylindrical glands 

 or Cffica («, figs. 1, 19), wliich are coiled vertically, side by side, 

 above the posterior part of the pylorus. They open into the origin 

 of the intestine immediately behind the union of its muscular 

 wall with the reflexed cliitinous cuticle (f, figs. 17, 18), which forms 

 the valve guarding the opening of the pylorus into the intestine. 

 Slightly in advance of the valve separating the two regions of the 

 intestine, a long tubular cajcum (i/, fig. 19) arises and runs forward, 

 either on the I'ight or the left of the intestine, and is coiled either 

 horizontally or vertically by its side, in the upper posterior part of 

 the thoracic cavity. On entering the intestine, its diameter is nearly 

 half that of the latter, but it diminishes to a slender tube in the 

 terminal coiled portion. 



Reproductive System. — The internal reproductive organs are large 

 and conspicuous, being of a clear white color in the male and bright 

 red in the female, and lying partly exposed when the carapace and 

 the underlying dermal covering are removed (^, fig. 1), 



In the mature female the ovary consists of a pair of large cylin- 

 drical sacs filled with red ova, and which unite under the anterior 

 edge of the heart. In advance of this union each lobe extends for- 

 ward, by the side of the stomach, close to the carapace and then 

 turns sharply back and extends upon the roof of the branchial cavity 

 towards its apex. Behind the point of union the two lobes or sacs 

 pass backward under the edges of the branchial cavities, and then 

 turning downward unite with the posterior faces of two white sacs, 

 the spermatheca3. The spermathecje communicate with the exterior 

 through cylindrical cliitinous infoldiugs of the integument, the 

 external openings of which are on the sternum of the third segment 

 bearing ambulatory limbs. These two openings are on the anterior 

 faces of two ridges or swellings of the integument at the inner ends 

 of the grooves separating this segment fi'oni the preceding one. The 

 ovary, before turning down to these spermathecpo, sends back, either 

 on the right or the left, a jjrolongation which extends into the 

 abdomen and fills the median portion of its first two or three 

 seo-ments. Occasionally this backward prolongation is somewhat 

 developed from both lobes of the ovary at the same time, and the 

 organ then becomes more symmetrical. 



In the male the generative organs occupy the same general position 

 that the ovaries do in the female. The testes (<, fig. l) are two very 



