Chap. VIII. DIASTYLID^. 81 



Next to the extensive sections of tlie Stalk-eyed and 

 Sessile-eyed Crustacea, but more nearly allied to the 

 former than to the latter, comes the remarkable family 

 of the DiasUjlidse or Gumacea. The young, which Kröyer 

 took out of the 

 brood-pouch of n^ 

 the female, and ^ 

 which attained 

 one -fourth of Fig.52.i6 

 the length of 



their mother, resembled the adult animals almost in all 

 parts. Whether, as in Mysis and Ligia, a transformation 

 occurs within the brood -pouch, which is constructed in 

 the same way as in Mijsis, is not known.^^ The caudal 



^^ Fig. 52. Male of a Bodotria, magn. 10 diam. Note the long 

 inferior antennse, which are closely applied to the body, and of which 

 the apex is visible beneath the candal appendages. 



J" A trustworthy English Naturalist, Goodsir, described the brood- 

 pouch and eggs of Cuma as early as 1813. Kröyer, whose painstaking 

 care and conscientiousness is recognised with wonder by every one who 

 has met him on a common field of work, confirmed Goodsir's state- 

 ments in 184G, and, as above mentioned, took out of the brood-poucli 

 embryos advanced in development and resembling their parents. By 

 this the question whether the Diastylidse are full-grown animals or 

 larvEB, is completely and for ever set at rest, and only the famous names 

 of Agassiz, Dana and Milne-Edwards, who would recently reduce them 

 again to larvaj (see Van Beneden, ' Eech. sur la Faune littor. deBelgique,' 

 Crustace'es, pp. 73, 74), induce me, on the basis of numerous investiga- 

 tions of my own, to declare in Van Beneden's words ; " Parmi toutes les 

 formes embryonnaires de podophthalmes ou d'e'driophthalmes que nous 

 avons observe'es sur nos cotes, nous n'en avons pas vu ime seule qui eut 

 meme la moindre ressemblance avec un Cuma quelconque." The only 

 thing that suits the larvse of Hippolyte, Palxmon and Alplieus, in the 

 family character of the Cumacea as given by Kröyer which occupies 

 three pages (Kröyer, ' Naturh. Tidsskrift, Ny Ksekke,' Bd. ii. pp. 203— 

 206j is : " Duo autenuarum paria." And this, as is well known 



G 



