NO. 1659. AMERICAX SrECIE."^ OF BYNALPHEUS—COVTIERE: 



81 



The height of the telson, in the male, is 1.24 times its base and 5 times 

 its posterior margin; in the female, the height hardly exceeds the 

 base, and is 3.7 times the posterior margin. In the female, the spines 

 of the superior face are situated on the proximal third ; in the male, 

 on the jDroximal half. Between the inner spines of the posterior 

 margin, which are twice as long as the outer spines, there are three 

 plumose hairs. 



The external uropod bears two teeth on its margin, and near the 

 inner tooth a movable spine which is longer in the female. The 

 basal spine of the uropod is strong and curved. 



Fig. 49.— Synalpheu.s pectiniger, abdomex. 9 normal; A$, B?, C?, D9, different degrees 

 of variation in the form of the pleura; c(f, normal; ecf , abnormal. 



The eggs are ver}^ large and give rise to m^'sis larva\ I have men- 

 tioned above that this species at an overstocked station {Albatross 

 Station Xo. 2413, 320 males, 230 females) presents a considerable ex- 

 cess of males with a marked sterility of the females, as if the latter 

 were more or less completely castrated. All the females have the 

 fourth and fifth abdominal pleura ending in a sharp point, as in the 

 males; all, save two have the first pleuron spinous; in the very great 

 majority of the females, even when ovigerous, the second and third 



J*l-oc. N. M, vol. xxxvi— 00 G 



