18C5.] 205 



croscopically minute in pi'chts, so that they were inadvertently over- 

 looked by Osten Sacken ? * 



2nd. When alive these larvae were not at all clavate in front, neither 

 were the thoracic segments flattened above and below, as the larva 

 of picfus is described and figured by Osten Sacken, most probably from 

 alcoholic specimens. Yet after being immersed in alcohol for three 

 and a half months, both these characters made their appearance, although 

 the prothorax is still, as compared with the middle abdominal joints, 

 only as thirteen to eleven wide, even in the most strongly clavate spe- 

 cimens, whereas Osten Sacken figures that o? p ictus us in the proportion 

 of thirteen to seven. Since, however, he describes the prothorax of 

 pictus as " twice broader than long," which is also true of rohinise, the 

 above difierence is probably due to his specimens having been preserved 

 in too strong alcohol, so as to shrivel up the abdomen unduly. 



Srd. When recent, the prothorax is not " brownish-yellow," but 

 whitish like the rest of the body, with four transversely arranged, 

 roundish, brownish-yellow, dorsal spots. In the alcoholic specimens, 

 the entire body assumes a more or less brownish tinge on the dorsal 

 and ventral surface, which is less obvious laterally; but even then the 

 prothorax is usually no darker than the rest of the body. 



Besides the above two (Phytophagic) Species, there is a third species 



* Baron Osten Sacken has obligingly sent me one of the larvae from which his 

 descrij)tion was drawn, and which, as he says, was communicated to him by Dr. 

 Horn, "along with the pupa and the recently escajje J imago;" and it absolutely 

 has no feet at all and no vestiges of any feet, under the most powerful lens. 

 Now, even if we assume that Dr. Horn was mistaken as to the identity of his 

 larva, which, as Baron Osten Sacken well suggests, can scarcely have been the 

 case, to what imago could it pertain? If it pertained to any other Ceramby- 

 cifle — e. g. Chion gart/nnicus Fabr. which is our commonest hickory borer — then 

 there is the same anomaly of a Cerambycidous larva without any feet. If it 

 pertained to a Lamiide — e. g. Monohammtis tigrinus DeGeer, which, according to 

 Dr. Fitch, commonly inhabits the hickory in Pennsylvania — then we have the 

 other anomaly of a Lamiidous larva with its thoracic spiracle, not where ac- 

 cording to Erichson it ought to be, viz: in the fold between the pro- and meso- 

 thorax, which fold as it bears the front legs in robinujc must necessarily be 

 prothoracic and not mesothoracic, but on the side of the mesothorax as in Ce- 

 ramhyridoE. For not only does Osten Sacken describe his larva as having the 

 "spiracles normal," but I see with my own eyes that its thoracic spiracle is on 

 the side of the mesothorax. On the whole, I incline to believe that the larva 

 o{ A. pictus is really apod, and that oi A. robinicc really 6-footed ; but as this is 

 so remarkable an anomaly, it would be very desirable to verify the facts by fur- 

 ther observations. Mr. Cyrus Thomas describes a larva found in locust wood, 

 which he supposes to be that q{ A. robinicc, as having "six very minute feet." 

 (Tram. III. State Agr. Soc. V. p. 4.30.)— Dec. !•;, 1865. 



