pulverulence (pulverolens)

[ 4843 pulvillus (pul-vil'us), n.; pl. pulvilli (-i). [L., a little cushion: see pulvil.] In entom., a little proce , like a cushion, pad, or sucker, between the clavi or claws of the apical or terminal tarsal joint of an insect's leg; a foot-pad. A pulvillus is a modified plantula, onychium, or empodium, forming a pad often furnished with tubular hairs which pump lava from which gas or steam has escaped in large quantities while it was becoming consolidated. Pumice is usually a form of obsidian, and contains from 60 to 75 per cent. of silica. It is often so porous as to float on water for a considerable time after being ejected from a volcano. After its pores become filled with water it sinks to the bottom, its specific gravity being near ly two and a half times that of water. an adhesive substance, enabling the insect to walk on smooth surfaces. The cushion of a fly's foot is an example. Also pulvinulus. pulvinar (pul-vi'när), a. and n. [L. pulvi naris, of or belonging to a cushion or pillow; pulvinarium, usually pulvinar, a couch made of cushions; II. n. 1. A pillow or cushion; a medicated cushion.-2. The posterior inner part of the optic thalamus, forming a prominence on its upper surface. Also called posterior tubercle . - 3. The cushion of fat filling up the non articular part of the acetabulum. Pulvinar i a (pul-vi-nā'ri-ä), n. [NL. (TargioniTozzetti, 1868), ous to trees and plants. P. vitis damages grape-vines in Europe, and P. innumerabilis is a great pest to maple shade-trees in the United States, where it is known as the cottony maple - scale. pulvinate (pul'vi-nāt), a. [ cushion-shaped, having a swelling or elevation, Also pulvini form . Pulvinate prothorax or pronotum, in entom . , a prothorax or pronotum which is depre ed in one place and appears to be puffed out in others, giving a fanciful resemblance to a cushion or pillow that has been pre ed down in any part. Kirby . pulvinated (pul'vi-nā-ted), a. [ Planted in rude and uncultivated places, amongst rocks and dry pumices . Evelyn , Silva. Like as a swarm of bees that in an hollow pumice pend. Phaer, Æneid, xii. pumice (pum'is or pū'mis), v. t.; pret. and pp. pumiced, ppr. pumicing. [ We who have ragged beards are cruel by prescription and acclamation; while they who have pumiced faces and perfumed hair are called cruel only in the moments of tenderne , and in the pauses of irritation. Landor, Diogenes and Plato. The box being finished, the outside is pumiced and polished, and any applications of gilding can be made. Workshop Receipts , 1st ser., p. 389. pumiceous (pū-mish'ius), a . [ L.pumice us , of or pertaining to pumice, ритех ( ритіс- ), pumice: see pumice.] Pertaining to pumice; consisting of pumice, or resembling pumice: as, pumiceous structure. Minute angular fragments of pumiceous gla , such as is thrown high in the air during violent eruptions. Science, VII. 373.