MALACOSTRACA. 307 



congeners are probably related to certain ancient fossil forms (rom 

 i'aheozoic stiata, e.g. IJyutenocaris from the Cambrian. 



FIG. 1 60. Ncbalia. After Sars. 



SN. t Shell; /?./, first antennae; A. 2, second antennae; 7Y/., 8 thoracic 

 limbs ; A b. 4, Ab.b, fourth and sixth abdominal limbs. 



FIG. 161. Anaspides. After Caiman. 



, A. , antennae; Ex., rudimentary exopoclite ; G. t respiratory lamina 

 R.J, PR.8, seventh and eighth thoracic limbs or pereiopods ; PL.i t 



, ., 

 9> 6, first, second, and sixth abdominal limbs or pleopods. 



