Specimens of this substance, as well as of another insect-product of Persia, together with the insects themselves, were presented a few years ago to the British Museum by W. K. Loftus, Esq., who obtained them while engaged by the British Government on the question of the Turco-Persian boundaries. The precise determination of the species of these insects being a matter of doubt, they have at my request been lately examined by M. Jekel, of Paris, an entomologist with whom the family of _Curculionidae_ has long been an especial study. One of these insects M. Jekel has identified with a species of wide distribution; the other proving undescribed, he has drawn up a description of it, which, accompanied by a figure, I have the honour to lay before the Linnean Society. To this, I venture to add a few observations upon the productions to which I have alluded. The first of these is _Trehala_ or _Tricala_, under which name it formed part of the Collection of Materia Medica sent by M. Della Sudda, of Constantinople, to the Paris Exhibition of 1855, and since deposited in the Ecole de Pharmacie in Paris. _Trehala_ (fig. 2) consists of cocoons of an ovoid or globular form, about 3/4 of an inch in length; their inner surface is composed of a smooth, hard, dusky layer, external to which is a thick, rough, tuberculated coating of a greyish-white colour and earthy appearance. Some of the cocoons have attached to them the remains of the tomentose stalk of the plant upon which they were formed; others have portions of a tomentose spiny leaf built into them; and, more rarely, one finds portions of the flowering heads of the plant, a species of _Echinops_, similarly enclosed. Many of the cocoons are open at one end and empty; others have a longitudinal aperture, originally closed by the stalk of the plant, and still contain the insect; a few are entirely closed. Specimens of this insect, extracted from the cocoons sent to Paris, were examined in 1856 by my friend Mr. W. Wilson Saunders, who pronounced them to be _Larinus maculatus_ of Faldermann,--a determination also arrived at by M. Jekel from specimens presented by Mr. Loftus to the British Museum. Respecting these latter, one of which is represented in fig. 1, M. Jekel makes the following remarks:-- "LARINUS MACULATUS, _Faldermann, Faun. Transcauc._ ii. p. 228, 449, tab. 6. f. 10, et iii. p. 198.--_Schoenh. Gen. et Sp. Curcul._ iii. p. 112 et vii. 2. p. 7.--_Hochhuth, Bull. Moscou_, 1847, No. 2. p. 538 (var. [Greek: gamma]). "Var. [Greek: gamma]. _Larin. Onopordinis_, Sch. _loc. cit._ iii. p. 111 (excl. synon.).