ZOOLOGY. 



595 



Order 4. Kammschneckenartige Nayasseln. 



3513. Body cylindrical, horny, and distinctly annu- 

 late, maxillae, eyes, and mostly seven simple pairs of 

 feet, branchiae as cysts or leaves. 



Fam. 4. Capulidenartige, Walzenasseln. 



Body cylindrical, with five or seven pairs of feet, and 

 some branchial vesicles ; body and abdomen very puny. 

 The Lamodipoda ; Caprella, Cyamus. 



Fam. 5. Turbinidenartige, Seitenasseln. 



Body horny and distinctly ringed, mostly compressed, 

 with perfect maxillae ; seven pairs of thoracic feet and 

 branchial vesicles ; abdominal feet rudder-shaped. They 

 swim usually lying upon the side; many leap Amphipoda; 

 Flohkrebse or Gammarina. 



Fam. 6. Buccinidenartigej Sohlenasseln. 



Similar to the preceding family, but the body is de- 

 pressed, and the abdominal feet furnished with branchial 

 plates. The Isopoda ; Oniscida, to which belongs the 

 genus Armadillo. 



COHORT III. KRACKEN-CRUSTACEA KOBE. 



3514. Body not tripartite ; spiracula or air-openings ; 

 more than three pairs of feet, no wings. Here belong 

 the air-breathing Crustacea ; Scolopendrae, Acari, Scor- 

 pions, and Spiders. 



These animals are abruptly distinguished from the 

 preceding by a conversion of the branchiae into spiral- 

 shaped tracheae, which ramify and traverse the whole 

 body. They all therefore live in the air, and if they do 

 also dwell in the water, they still come to the surface to 

 inhale that element. The eyes are only simple points or 

 ocelli, which are accumulated frequently upon the sides 

 of the head. 



The most inferior of them are distinguished from the 

 preceding cohort, or the Asseln, by almost nothing 

 save the essential character of their own cohort, the tra- 

 cheae. They have mostly a number of feet, and only 

 simple eyes, as the Scolopendrae. 



