286 Puget Sound Marine Sta. Pub. Vol. 1, No. 26 



The above Decapoda were studied in part at the Puget Sound Marine 

 Station, but the bulk of the investigation was carried on in the zoological 

 laboratories of the University of Washington during the fall, winter and 

 spring months of 1916-1917. 



2. MALE REPRODUCTIVE ORGANS OF BRACHYURA 



The male reproductive organs of Cancer gracilis. Cancer oregonensis, 

 Scyra acutifrons and Lophopanopeus bellus closely resemble the same 

 structures in the other Brachyura discussed in my previous paper (Fasten, 

 1915). These organs are located in the chamber of the cephalothorax and 

 when fully developed they occupy the main portion of this cavity (See 

 Figs. l-i). The organs lie directly below the heart and above the diges- 

 tive glands or the so-called liver. The testis (Figs. 1-4, t) , which com- 

 prises the main part of the male reproductive organs, is bilobed and pro- 

 fusely tubular in structure. Each testicular lobe is found in the upper 

 part of the cephalothoracic region, and extends laterally along the stom- 

 ach. Both lobes unite in the median plane of the body (Figs. 1-4, .r), un- 

 derneath the anterior portion of the heart. Near this junction point two 

 slender tubes (Figs. 1-4, v. d.) make their origin, the so called vasa defer- 

 entia, one tube originating from each testicular lobe. These run posteri- 

 orly to the base of the fifth pair of walking legs, where they open to the 

 outside. 



In Cancer gracilis (Fig. 1), the male reproductive organs resemble 

 those of Cancer productus very closely (Compare Fig. 1 with Fig. 1 on p. 

 37 of Fasten, 1915). In Cancer oregonensis (Fig. 2), all parts of the 

 male reproductive organs are massively developed. The testis (Fig. 2, t) 

 fills in almost comjjletely the upper lateral spaces of the cephalothorax, 

 while the vas deferent tubes (Fig. 2, v. d.) are thick structures tightly 

 coiled in the chamber between the heart and the intestine. 



In the sharp-nosed crab, Scyra acutifrons (Fig. 3) the testis is found 

 to resemble that of the decorative crabs Hyas lyratus and Oregonia gracilis 

 (Compare Fig. 3, t. with Figs. 3 and 4, t, page 39 of Fasten, 1915). The 

 vasa deferentia of Scyra acutifrons (Fig. 3, v. d.), however, do not pos- 

 sess the diverticula found in the vasa deferentia of Hyas lyratus or Ore- 

 gonia gracilis (See Figs. 3 and 4, v. d., page 39 of Fasten, 1915). In the 

 black-clawed crab, Lophopanopeus bellus (Fig. 4), the portions of the male 

 reproductive organs are built according to the plan outlined. However, 

 the vasa deferentia (Fig. 4, v. d.), are profusely coiled just below the 

 region where they leave the testicular lobes. 



3. MALE REPRODUCTIVE ORGANS OF ANOMURA 



The male reproductive organs of the Anomura, in both sexes, differ 



