found in the Interior of a False Acacia. 531 



those of the Yponomeuta Evonymella, the very common little 

 ermine moth, construct their cocoons " a un des bouts de leur 

 dernier nid." In the first part of the Transactions of the 

 Entomological Society, I have published an account of a gre- 

 garious species of Mexican butterfly, in which the chrysalides 

 are arranged within the nest formed by the caterpillars, and 

 which very nearly resembles that of some of the wasps ; and 

 in a memoir upon the pomegranate ^butterfly of the East 

 Indies, not yet published, I have shown that the chrysalides 

 are placed in society inside the fruit, although the larva must, 

 immediately previously to assuming that state, have made its 

 way to the outside of the fruit, and then returned. But the 

 following particulars, communicated to me by Mr. Denson, 

 relate to a species of moth which not only retains its grega- 

 rious habits during the caterpillar and pupa states, but also 

 arranges its cocoons so compactly together, that it seems dif- 

 ficult to imagine how the moths, on arriving at the perfect 

 state, could make their escape. Mr. Denson forwarded to me 

 a mass of spongy-looking matter, wrapped in a piece of paper, 

 in which a number of dead moths were also enclosed. The 

 former measured about 5 in. in length, and 2\ in. in diameter. 

 It was discovered in May, 1835, in a locust tree, or common, 

 or false, acacia (RobinzVz Pseud-^cacia L.), which stands 

 upon the lawn in the private botanic garden of Mrs. Canham 

 (formerly of Isaac Swainson, Esq.) ; and Mr. Castles, the 

 curator of the garden, by whom it was found, thinks that 

 the tree may be 70 or 80 years of age. It is in the condition 

 of life and growth mixed with decay and disease. At the 

 base of the stem, at a point of aspect nearly north-west, is 

 a largish opening to a hollow in the tree, which extends up 

 the stem for more than a foot from the ground ; and the wood 

 of the interior of the tree, which bounds the hollow, is in a 

 decayed state. It was in this hollow, and at about one foot 

 from the bottom, and attached or contiguous to the decayed 

 wood of the tree, that two masses were found, the one above 

 described being the larger of the two. Mr. Castles broke 

 the smaller mass open, and found it to contain chrysalides. 

 The latter he preserved entire, and from it the moths 

 subsequently burst forth. On opening the larger mass, a very 

 great number (between 200 and 300) of cocoons, containing 

 the exuviae of chrysalides, were found closely packed together, 

 each being about an inch long. These cocoons were not 

 arranged in order, some being transversely, and others lon- 

 gitudinally placed. The chrysalis is of the ordinary conical 

 form. The moth is the Ilithyia Latr. sociella Lin?i., a 



