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pterous larvae, there are ten abdominal segments. In the larvae before 

 the last molt there is a pair of rudimentary abdominal legs on the se- 

 cond abdominal segment, forming soft tubercles about one-third as 

 large as the succeeding normal feet ; the crown of hooks was wanting, 

 but a tubercle on the anterior side corresponding to a similar one on 

 the normal feet had five or six well marked stout spines, also two or 

 three scattered ones in the middle, the tubercle being rounded, con- 

 vex, not flattened at the end. 



On the sixth segment, following the fourth pair of normal abdo- 

 minal legs , is a pair of tubercles like those on the second segment 

 and exactly corresponding in situation with the normal legs ; situated 

 externally are two long straight spines , but none homologous with 

 those forming the crown. At the base in front of each tubercle is a 

 tuft of sparse hairs, and on the outside is a chitinous spot bearing a 

 dense tuft of hairs ; these two tufts precisely agree in situation and 

 appearance with those at the base of normal abdominal legs. 



In the fully fed caterpillar the tubercles are exactly the same. 

 It thus appears that in the Lagoa larva the first abdominal segment is 

 footless; the second bears rudimentary feet; segments 3 — 6 bear nor- 

 mal proplegs ; the seventh bears a pair of rudimentary legs ; segments 

 eight and nine are footless, while the tenth bears the fully developed 

 anal or fifth pair of genuine proplegs. 



While these two pairs of tubercles difiier from the normal legs in 

 being much smaller and without a crown of curved spines , they are 

 protruded and actively engaged in locomotion, and in situation, as 

 well as the presence of the basal tufts are truly homologous with the 

 normal abdominal legs. 



As this case is unique, no other Lepidopterous larva (except the 

 allied Chrysopyga ^) being known to possess more than five pairs of ab- 

 dominal legs, we for the third time carefully and repeatedly observed 

 the caterpillar when alive, and watched the movements of the abdomi- 

 nal legs during locomotion, and saw how the two rudimentary pairs, 

 viz., those on the 2d and 7th abdominal segments were raised and put 

 down. With the triplet in hand and allowing the larva to walk on the 

 edge of the tin box in which they had been confined , it was easy to 

 see that the above mentioned proplegs were actively used , performing 

 the same general acts of extension and retraction of the planta, as the 



1 Within the past year I find that Dr. H. Burmeister had described in 1879 

 in his elaborate Atlas de la description physique de la République Argentine, Lépi- 

 doptères, PI. XXII, Figs. 6, 6^, 6^, 6 C the larva of Chrysopyga undulata, -which 

 is closely allied to Lagoa and has similar abdominal legs, those on the 2d and 7th 

 segments being wart-like and without crotchets. 



