PRANIZA. 239 



on the sides, with lamellar pieces belonging to the last pair 

 of false legs; the last segment of the abdomen is always 

 lamellar and much larger than the segments before it. The 

 legs are short, and formed for walking or for holding on. 



Fam. PRANIZID^J. 

 In this family the thorax is composed of five rings, and 

 the limbs corresponding to the two first pairs of legs are 

 rudimentary, or wanting. The five last pairs of legs are 

 slender and formed for walking. Abdomen narrow, but well 

 developed. 



Gen. 122. PKANIZA, Leach. 



Praniza are minute marine Crustacea. By means of their 

 legs they can creep on the bottom, which they do slowly; 

 but they swim with greater rapidity, propelling themselves 

 forwards by the quick motions of a series of ciliated fins 

 placed beneath the tail. Of their economy nothing is known. 

 They are characterized by having four unequal antennse ; two 

 sessile eyes ; an elongated body divided into three segments, 

 of which the two anterior, or thoracic, are very small, and 

 the third, or abdominal, very large. They have ten legs, a 



