Titlebook: Systema Porifera; A Guide to the Class John N. A. Hooper,Rob W. M. Soest,Philippe Willenz Book 2002 Springer Science+Business Media New Yor

Feature

ITCH

,‘Class Stromatoporoidea’ Nicholson & Murie, 1878: Stromatoporoids,, comprising sponge-like taxa with hypercalcified layered skeletons that were important to reef-building. Earlier (Palaeozoic) forms lack spicules but some of the later (Mesozoic) taxa have siliceous monaxonomic or tetraxonic spicules in addition to calcitic basal skeletons, inferring affinities to

indifferent

Order Homosclerophorida Dendy, 1905, Family Plakinidae Schulze, 1880,e Vosmaer), with seven valid genera and about 60 valid species worldwide. Species live mainly in shallow waters but a few have been recorded from abyssal depths (up to 2460m). Species are often encrusting, lobate, but massive species are common in some genera (.); surface is usually smooth or microh

Finasteride

Order Spirophorida Bergquist & Hogg, 1969,or s-shaped spicules of 10–40 μm length). Triaenes and tetractine spicules are shared with sponges of the order Astrophorida, but are absent in some taxa. Sigmaspires are shared with the lithistid family Scleritodermidae, which points to a probable close relationship with this family, once again dem

珠宝

Family Tetillidae Sollas, 1886,heir possession of sigmaspire microscleres and triaene megascleres. The characteristic megasclere is the protriaene, which is found in most members of the family with very few exceptions. In addition there are long oxeas and frequently anatriaenes, rarely also calthrops or amphitriaenes. The skeleta

单片眼镜

Gleason-score

Family Spirasigmidae Hallmann, 1912,Indian Oceans. They are thinly encrusting to small conical shapes, with radial skeletons that fan out and become plumose in the periphery where they become nearly tangential at the surface, composed of large strongyloxeas. One genus (.) also has a secondary disorganised skeleton of roughened `microx

记忆

enormous

雪上轻舟飞过

Family Calthropellidae Lendenfeld, 1907,trellidae. With Ancorinidae (+ Geodiidae) they share the possession of euasters, and with Pachastrellidae they share calthrops-like megascleres. There are no unique features, and it is suspected that the family may turn out to be artificial. All genera have calthrops and euaster microscleres, and so