— 28 — 



Remarks. — The material examinée! is exceedingly rich, 

 viz.no less than 65 spécimens, comprising every stage of froni less 

 than half-grown to full-grown spécimens of both sexes. I have 

 therefore been able to trace the variation according to âge and 

 sex of various features, with the resuit that I consider two 

 species established by Sars and a third erected by Chun as 

 various stages of both sexes of this species. In adult females 

 the carapace is without latéral marginal denticles, but in rather 

 large immature females and in adult and subadult maies small 

 denticles are found, while in half-grown or still smaller spécimens 

 they are even very conspicuous. My small spécimens are less 

 than half-grown, and they agrée as to the shape of the front 

 portion of the carapace, latéral denticles and 5 spines on the 

 terminal joint of the elongate legs, with N. rostrata, G. O. Sars. 

 The adult females agrée well with Sars, fig. i ; according to kind 

 information from Dr. Caïman one of the two spécimens in the 

 British Muséum « is from the Pacific, ovigerous, mounted on a 

 « slide and marked by Sars as the « Type ». This is no doubt 

 « the original of his fig. i. The other is from the Atlantic 

 « and is probably the original of his fig. 2 ». A sketch 

 forwarded by Dr. Caïman of the rostrum of the latter spécimen 

 agrées rather well with fig. 2 of Sars, but this rostrum is 

 shaped as in subadult females, while in the ovigerous females 

 studied by me the rostrum is somewhat more narrow at its 

 middle, its distal half therefore more subulate than on the figure 

 mentioned. Sars states that N. microps has 6 spines on the 

 last joint of the elongate legs, but Caïman writes to me that 

 « it [the terminal] joint has seven spines, as you suppose, in 

 both spécimens ». Chun describes and figures 7 spines in his 

 single (maie) spécimen on which he established N. mantis ; his 

 figure of rostrum agrées with that in subadult maies, while in 

 completely developed spécimens of this sex the front end of the 

 carapace is shaped as a low triangle with its angular apex 

 measuring about 90 0 , thus without any elongate process ; in 

 such adult maies the copulatory organs of first pleopods are 

 still more complicate than shown in Chun's fig. 7. Chun found 

 that his maie had two spermatophores in vasa deferentia, 



