ORDER STOMAPODA ; PHYLLOSOMA, OR GLASS-CRAB. 257 



all for walking. This species is probably the largest of the 

 Order ; its length being about seven inches. It is common in 

 the Mediterranean. 



792. To this Order also belongs a very curious genus, the 

 Phyllosoma, or Glass-Crab. Its scientific name, which means 

 leaf-bodied, as well as its common designation, refer to the 

 remarkable peculiarity of structure by which it is distinguished ; 

 the whole body being flattened like a leaf, and almost as trans- 

 parent as glass. It is composed of a large oval plate, which 

 represents the head, and bears the two eyes, mounted on 

 long footstalks, at its anterior extremity ; of a second plate, 

 in part covered by the preceding, and giving insertion to the 

 thoracic legs ; and of an abdomen which is always short, and 

 in some species undeveloped. The legs, six in number, are very 

 long and slender ; they are bifid or divided into two, like those 

 of the Mysis ; and are adapted for swimming only. These 

 curious creatures are inhabitants of the tropical parts of the 

 Atlantic and Eastern Oceans. 



793. It is scarcely possible to avoid being struck by the 

 analogy presented by this Order, to the Orthoptera among 

 Insects. The resemblance of the Squilla to the Mantis has already 

 been noticed ; and the correspondence of the Phyllosoma to the 

 leaf-like species of the same order ( 653), is scarcely less 

 remarkable. We may also point out the many resemblances 

 between the Decapod Crustacea, and the Coleopterous Insects. 

 They occupy a corresponding position, in being at the head of 

 the mandibulate series of their respective classes ; they are both 

 also pre-eminent in regard to the hardness of their integuments ; 

 and in both there is an adaptation of the extremities for walking, 

 rather than for swimming or flying which are actions analogous 

 to each other (ANIM. PHYSIOL., 663). 



