36 Piiget Sound Marine Sta. Pub. Vol. 1, No. 7 



nudus {Fig. 6), and in Telmessus chiragoniis {Fig. 7), the lobes of the 

 testis {t), their union {x), and the vasa deferentia {v. d.), conform 

 more or less to the same plan of these elements in the edible crabs^ 

 Cancer productus and Cancer magister, as described above. 



When the kelp crabs are studied, one finds that the male repro- 

 ductive organs of the graceful kelp crab, Pugettia gracilis {Fig. 9), 

 conforms to the types already described. The common kelp crab, Epialtus 

 productus, however, varies somewhat from the type. Here the lobes of 

 the testis {Fig. 8, t) are massive, and before uniting they each thin out 

 into a very slender tubule. These tubules become united medianally 

 {Fig. 8, x), and from their junction the vasa deferentia {Fig. 8, v. d.) 

 make their origin. 



In the decorative crabs, Hyas lyratus {Fig. 3) and Oregonia gracilis 

 {Fig. 4), the vas deferent ducts {Figs. 3 and. 4>, v. d.) show interesting 

 modifications. Here these structures are not straight tubes, but from 

 the main ducts are given off numerous side branches in the form of blind 

 tubules (diverticula), giving each of the vasa deferentia the appearance 

 of a root system, the central root representing the main tube, and the 

 rootlets representing the blindly projecting tubules. Figure 5 is an 

 enlarged drawing of the terminal portion of one of the vas deferent 

 ducts of Oregonia gracilis to show its structure. In Hyas lyratus the 

 projecting tubules (diverticula) are developed to a greater degree. 



PLATE t 



Abbreviations — /=testis ; ct'=unioii of two lobes of testis ; v. d.^vasa. 

 deferentia. 



Fig. 1. Cancer productus. XI- 



I'ig. 2. Cancer magister. XI- 



