i 



270 THE DEEP-SEA CRUSTACEA 



series of metamorphoses. It also shows us that the 

 preservation of many of the deep-sea species is best 

 assured, not by the irresponsible scattering abroad of 

 a vast multitude of larvae, but by protracted parental 

 attention to a limited number of offspring. This 

 indeed is an inference which we might have gleaned 

 from our study of the Teleostean fishes of the deep 

 sea, many of which have very large eggs, and several 

 of which are viviparous. Among the sedentary deep- 

 sea Crustacea large eggs are characteristic of the 

 extensive genera Munidopsis and Glyphocrangon, The 

 figure of Plastocrangon cceca (Fig. 56) shows examples 

 of these large eggs, attached, in the usual place, to the 

 swimming legs of the mother. Numerous active species 

 also produce large eggs, the largest of all being credited 

 to Psathyrocaris platyophthalmus, a little creature which, 

 though not much more than 3J inches in length, lays 

 eggs nearly quarter of an inch long. On the other 

 hand, most of the active deep-sea Crustacea, which 

 swim in the canopy of the waters—such as Acanth- 

 ephyra^ Nematocarcinus^ and the PandalidcB (^Dorodotes 

 excepted) ^ — and even some such undoubted abyssal 

 forms as Polycheles and Pentacheles lay a multitude 

 of small eggs, as also do most but not all of the 

 deep - sea crabs. Dorodotes reflexus is singular in 

 producing, at one brood, eggs of two kinds, namely, 

 large eggs which give rise to young, and small 

 eggs whose role is not known, unless they are to 



