Linnaan Society. 395 



presence. The total absence of male sacs, and the rarity of ova in 

 the females, may, Mr. Huxley thinks, be accounted for by the season 

 during which his investigations were cai-ried on, the months of 

 March, April, May and June being the winter of the Southern 

 Hemisphere. Lastly, the author enters on the comparative anatomy 

 of various species of Physophorida, by means of which he believes it 

 to be satisfactorily demonstrated that there exists a unity of organi- 

 zation between the two families of Diphyidce and Physophoridce ; and 

 concludes by stating his opinion that at least two other families, the 

 Hydriforra and Sertularian Polypes, should be arranged with them in 

 one natural group. The structural coincidences in these families he 

 enumerates as follows : 1. body composed of two membranes, out of 

 ■which the organs are modeled; 2. thread-cells universally (?) pre- 

 sent ; 3. gemmiparous generation ; 4. sexual generation, sperma- 

 tozoa and ova being formed in vase-like external sacs. 



The paper was accompanied with a series of illustrative drawings. 



March 5. — William Yarrell, Esq., V.P., in the Chair. 



Dr. Wallich, V.P.L.S., read the following extract of a letter from 

 Prof. Lehmr.nn, dated Hamburgh, I4th December, 1849 : — " I write 

 to inform you that a work has just appeared, namely Proceedings of 

 the Fifth Meeting of Scandinavian Naturalists held at Copenhagen 

 1847. Copenhagen, 1849. 8vo. There is in it a very remarkable paper 

 by Liebmann, entitled ' A few words concerning the Impregnation of 

 Cycadea,' p. 501 seq. It appears, according to this paper, that in 

 that family ripe and vegetative fruits may be produced, without the 

 process of impregnation. A female plant in the Botanic Garden at 

 Copenhagen (males do not exist in Europe) produced seeds which 

 have germinated ! Liebmann made the same observation in Mexico." 



Read also a paper entitled, "Further observations on the habits 

 of Monodontomerus, with some account of a new Acarus, Heteropus 

 ventricosus, a parasite in the nests of Anthophora retusa." By George 

 Newport, Esq., F.R.S.. F.L.S. &c. &c. 



Mr. Newport remarked that as some of the details of a pa2:)er on 

 " certain Clialcididce and Ichneumonid(B" read to the Linnean Society 

 in March 1849 had drawn forth at that time the dissent of some en- 

 tomologists, he had repeated his observations during the past sum- 

 mer, and on one occasion had obtained as many as tivo hundred and 

 forty-seven larvae of Monodontomeri from the nests of Anthophora. 

 In every instance these parasites had fed on the bee larva yVow ivith- 

 out, and had drained it of its contents in the same way that the 

 larva of Panisciis drains that of the body of a caterpillar, thus proving 

 the correctness of his original statement, that the Monodontomeri are 

 ejcternal and not internal feeding parasites. He had originally been 

 led to this view, not, as erroneously stated by Mr. Westwood in the 

 printed Proceedings of the Linnean Society for May 1849, p. 37 

 (Annals and Mag. Nat. History, Oct. 1849, p. 288), from the simple 

 fact that the author had found the bodies of these parasites covered 

 with an armature of hairs, but as he had explicitly stated in his 

 former paper, from the circumstuuce tliat lie had never found hairs 



26* 



