14 MEMOIR II. 



our notice, in being* provided with a quadruple row of feet 

 or members, and with hands vastly more complicated and 

 beautiful than in man, or any known creature, there could 

 hardly be found a subject more worthy to eng^age our con- 

 templation, or more capable of inspiring us with adoration 

 of the Divine Perfection, as manifested in the minuter 

 works of creation. 



It will hardly be credited that such interesting peculiari- 

 ties could have remained unnoticed, when it is known, 

 that the Opossum Shrimps are in these climates the most 

 common of all the Crustacea, that they abound to such a 

 degree, as to astonish by their countless myriads, and that 

 (unlike all the other animals of their class) they offer 

 themselves freely to our view when we stroll along the 

 margin of our estuaries, where, particularly in spring and 

 summer, they may be observed forming an almost conti- 

 nuous band or column of some feet in breadth, extending 

 along either margin of the tide, from the sea up to where 

 the water becomes almost fresh. If we stop to consider 

 so singular a piece of negligence, it only furnishes a proof 

 of the little attention that has hitherto been paid to this 

 class of animals. 



The Opossum Shrimps belong to a small group of the 

 Crustacea, at present embracing but three or four Genera, 

 which it is proposed to develope in succeeding Memoirs, 

 as they are for the most part nondescript, and in other 

 respects highly interesting; this group has been designated 

 by modern systematists as a family, mider the title ot 

 Shizopoda or Fissipedes, from the singular circumstance 

 of having all their feet or members divided to their very 

 origin into two parts or limbs, the inner limb being con- 

 structed for progression and the seizing of their prey, and 

 the outer one for swimming and the giving that motion 

 to the water which is essential to the respiratory organs ; 

 which organs, with a view to the due oxigenation of their 

 circulating fluid, are as it were wrapped around the base 



