ANOMURA — GALATHEIDEA 



169 



Galathea, are littoral animals, and may be 

 found hiding under stones and in crevices 

 on the shore ; but a number occur in deep 

 water, e.g. 3Iunida and Mic7iidopsis. 



The shallow -water species have ordin- 

 arily developed eyes ; the various species of 

 Munida, which occur in fairly deep but by 

 no means abyssal regions, have usually very 

 large and highly pigmented eyes ; while in 

 Munidopsis, which is characteristic of very 

 deep water, the eyes are degenerate and 

 colourless, as shown in Fig. 114. 



The Zoaeae, or young larval stages of 

 the Galatheidea, are cliaracterised by the 

 immense length of the spines upon the 

 carapace (Fig. 115). The young Zoaea 

 whicli hatches out from the egg resembles 

 in other respects that of the Brachyura. 

 The Metazoaea, however, differs from that 

 of the Brachyura in the fact that the third 

 maxillipede is first present as a biramous 

 swimming organ, and at its first appear- 

 ance is not developed in its definitive form. 

 The other thoracic limbs are not schizo- 

 podous when they appear, and indeed in 

 nearly all respects the development proceeds 

 as in the Brachyura. 



Fam. 1. Aegleidae. — The gills are tri- 

 chobranchiae, and there are eight arthro- 

 branchs. There are no limbs on the 

 second abdominal segment of the male. 

 The abdomen is not carried folded on to 

 the thorax. The first two characteristics 

 separate this family from all the other 

 Galatheidea. Aeglca laevis, a fresh -water 

 species from the rivers of temperate S. 

 America, is the sole representative. 



Fam. 2. Galatheidae. — The abdomen is 

 not folded against the thorax. The mem- Fig. 115. 

 hers of this family are often littoral in 



Zoaea of 

 Porcellana, x 20. 

 T, Telson. (After 

 Claus.) 



