E. A. Andrews — Anatomy of the Spider Crab. 113 



long, slender tubules forming on either side of the stomach a much 

 convoluted mass, which resembles in shape and position the corre- 

 sponding lobe of the ovary and is like that united to its fellow under 

 the anterior edge of the heart. Behind this union the tubules expand, 

 forming on either side, beneath the heart, a convoluted tub6 {f, fig. 

 1), which becomes posteriorly still larger and less convoluted and 

 extends back to the opening in the chitinous roof of the posterior 

 apodemal cell. Befoi-e passing through these openings these tubes 

 or ducts receive the secretions of a pair of large glands {t", fig. 1) 

 filling most of the space between the carapace and the posterior 

 apodemal cells. These glands are composed of large, translucent, 

 irregiilarly branched sacs or tubes containing a viscid adhesive 

 substance. The ducts having passed- into the posterior apodemal 

 cells become much more slender, but have a much firmer wall. 

 They pass forward and then turn backward through these cells 

 and enter the basal joints of the posterior ambulatory legs, where 

 their walls become continuous with the chitinous, cuticular covering 

 of the penis. These organs ai-e short papillae arising from the lower 

 inner edges of the basal segments of the posterior legs and are 

 clothed with setse on the side towards the median line. The tip 

 can be somewhat invaginated. 



Circulatory System. — The heart (/i, fig. 1) is a large pentagonal 

 disk lying in the pericardial sinufe immediately under the central por- 

 tion of the carapace, between the apices of the two branchial cham- 

 bers. It communicates with the pericardium through six apertures, 

 four on the u})per surface and one on each of the antero-lateral faces, 

 which are guarded by valves opening inward. It is held in place by 

 three fibrous bands connecting its upper surface with the integument, 

 by a similar band on each side connecting it with the edge of the 

 branchial chamber, by its contact with the floor and anterior wall of 

 the pericardium («^9, fig. 1) and by the arteries arising from it. 



Of these arteries, three arise from the anterior angle of the heart. 

 The median one (?•'), the ophthalmic artery, runs straight forward 

 close to the integument over the stomach, without giving oif many 

 branches, and passing between the anterior gastric muscles it ex- 

 tends down in front of that organ, giving branches to the eye-pedun- 

 cles and to the rostrum. The other two (r), arising on either side of 

 the median one, are the antennary arteries, and run forward and 

 outward parallel to the stomach and close to the dermis till they meet 

 the portions of the reproductive organs which turn outward ; under 

 these they pass and continue forward into the antennae. From them 



