_Samia Gloveri_.--Three North American silk-producing bombyces, very closely allied, have been mentioned in my previous reports; they are; _Samia ceanothi_, from California; _Samia gloveri_, from Utah and Arizona; and _Samia cecropia_, commonly found in most of the Northern States--the latter is the best and largest silk producer. Crossings of these species took places in 1880, and, as I stated before, the ova obtained from a long pairing between a Ceanothi female with a Gloveri male, were the only ones which were fertile. The Gloveri cocoons received in 1880 were of a very inferior quality, and produced moths from which no pairings could be obtained, although some crossings took place. In 1881, the Gloveri cocoons, on the contrary, produced fine, healthy moths; yet only five pairings could be obtained, with about one hundred cocoons. Besides these five pairings, a quantity of fertile ova were obtained by the crossings of _S. gloveri_ (female) with _S. cecropia_ (male), and Cecropia (female) with Gloveri (male). No success, so far as I know, was obtained with the rearing of the hybrid larvæ; the rearings of the larvæ of pure Gloveri were also, I think, a failure, only one correspondent having been successful; but some correspondents have not yet made the result of their experiments known to me. The larvæ of _Samia cecropia, S. gloveri_, and _S. ceanothi_, are very much alike; and hardly any difference can be observed in the first two stages. In the third and fourth stages, the larvæ of _S. cecropia_ and _S. gloveri_ are also nearly alike; the principal difference between these two species and _S. cecropia_ being that the tubercles on the back are of a uniform color--orange-red, or yellow--while on Cecropia the first four dorsal tubercles are red, and the rest yellow. The tubercles on the sides are blue on the three species. The larvæ of the hybrids _Gloveri-cecropia_ were, as far as I could observe, like those of Cecropia, but I noticed some with six red tubercles on the back instead of four, as on Cecropia. They were reared on plum, apple, and _Salix caprea_; in the open air. The larvæ of _Samia gloveri_ were reared, during the first four stages on a wild plum-tree, then on _Salix, caprea_, and I reproduce the notes taken on this species, which I bred this year (1881) for the first time. Gloveri moths emerged from the 15th of May to the end of June; five pairings took place as follows: 1st, 4th, 9th, 24th, and 26th of June. First stage--larvæ quite black. Second stage--larvæ orange, with black spines. Third stage--dorsal spines, orange-red; spines on sides blue. Fourth stage--dorsal spines, orange or yellow, spines on the sides blue; body light blue on the back, and greenish yellow on the sides; head, green; legs, yellow. Fifth and sixth stage--larvæ nearly the same; tubercles on the back yellow, the first four having a black ring at the base; side tubercles ivory-white, with a dark-blue base.