Entomological Society. 4963 



The Rev. Hamlet Clark exhibited a new British species of Hydroporus, recently 

 detected by him in the collection of Mr. Waterhouse. 



Mr. Stevens exhibited a box of Coleoptera recently received from Mr. Wallace, at 

 Borneo, containing many new and fine species, especially amongst the Longicorns. 



Mr. Newman read the following notes, exhibiting the insects to which reference is 

 made: — 



Silk-spinning Acarus of the Furze , See. 



" I beg to exhibit a mass of silk spun by a minute Acarus, and obligingly handed 

 me, together with multitudes of the little specimens, by Dr. Milner Barry, of Tunbridge 

 Wells, who writes as follows: — 'When strolling across Rusthall Common this after- 

 noon I noticed some red powder lying in thick cobwebs entangled in the furze: I took 

 up some of the powder, and found it was living and moving, and consisted of myriads 

 of vivacious red insects resembling Acari.' When the mass reached my hands it was 

 of the size and shape of a sparrow's egg, the Acari running over it in all directions, 

 and each adding to the bulk by leaving behind him a continuous thread of the finest 

 conceivable silk. I subsequently sent the mass to Mr. Meade, the Arachnologist, who 

 has carefully examined it, and kindly sent me the following information: — 'The 

 minute animals inhabiting the curious cocoon you sent me are Acari, belonging to the 

 genus Tetranychus of Dufour, the type of which is the little red spider so injurious to 

 plants in hot-houses and rooms, the Acarus telarius of Linneus : most of the species 

 live in society, on plants, and possess the power of forming webs : Koch says, when 

 speaking of an allied species, Tetranychus socius, ' It appears in certain years in such 

 numbers that it covers the trunks and the branches of the lime-trees which it frequents, 

 with such a thick web that they look as if clothed with glazed satin.' I cannot find 

 any description of the species sent by you, although it is closely allied to the common 

 Tetranychus telarius, and I never before saw or found anything like the curious nest 

 which it inhabits.' Since the receipt of Mr. Meade's note I have paid some little 

 attention to the Tetranychus telarius, and find that the net-work of infinitely minute 

 silken threads is admirably adapted to its singularly formed feet, and these are equally 

 well adapted to the office of holding on while it perforates the cuticle of the leaf with 

 its rostrum : its hold is so secure that no amount of washing by means of a garden- 

 engine seems to have the effect of removing it: as I have no doubt whatever that these 

 little creatures are exclusively vegetable-feeders, the web cannot serve, as in spiders, 

 the purpose of securing prey, and it is, moreover, never accompanied by the glutinous 

 particles which render the web of spiders so adhesive : as a matter of course, if the 

 Acari can resist the action of a water-engine they have little to fear from the effects of 

 rain." 



An Australian Bombyx escaping from its Cocoon in England. 



" I beg to exhibit a male specimen of the Entometa obliqua of Walker, an 

 Australian moth, allied apparently to Zeuzera, (Eceticus and Psyche: the insect 

 has recently emerged from a sack-formed cocoon, and had it escaped and been 

 captured on the wing it would doubtless have found a place in our catalogues. 

 Mr. Oxley, to whom I am indebted for the loan of the specimen, exhibited the 

 cocoon, amongst others, at one of our meetings last year, and adds the following 

 information : — ' Although I am unable to state at what date the cocoon in question 



