80 THE BUTTERFLY VIVARIUM. 



segments. Then occur two segments without feet, 

 and then another pair on the anal or last segment. 



Some of the "False Caterpillars," as they have 

 been termed, have as many as fourteen and sixteen 

 spurious feet (or pro-legs, or pro-feet), as in the 

 cases of Tenthredo cerasi and other kinds of Ten- 

 thredo ; while a large class of true Lepidopterous 

 larvse is entirely without the pro-feet of the ventral 

 segments. These are the " Loopers ;" the Half- 

 loopers having only two pairs. The absence of the 

 ventral legs in the true Loopers obliges the larva, 

 when in motion, to bring up those situated at the 

 anal segments close to the segments which are fur- 

 nished with the pectoral legs, thus forming the body 

 into a loop, and then advancing the anterior portion 

 of the body till it becomes straight, the anal pro- 

 legs being again brought up as before. It is this 

 action which has suggested the name of Earth 

 Measurers or Geometroz. 



Some Caterpillars walk much more swiftly than 

 others, while some, it is said, can even leap. Dc 

 Geer and Iloesel mention the Caterpillars of I/lthosia 

 Quadra and Hermmia Bostralis as having this 

 power. This depends, doubtless, on the formation 

 of the pro-feet, which differ much in structure, some 

 having hooks, others none. There are some curious 



