本分類原最初由1883年由法國動物學家保羅·亨利·菲舍爾（德语：Paul Henri Fischer (Malakologe)）設置，當時包括側鰓海牛屬（英语：Pleurobranchus）（Pleurobranchus）及傘螺屬（英语：Umbraculum (gastropod)）（Umbrella）兩屬，並歸類於覆鰓類（英语：Tectibranchia）（Tectibranchiata）之中[2]。4
背楯類物種包括有海蛞蝓和一種被稱為「假笠貝」的海洋腹足綱軟體動物的分類，直腹足亞綱後生腹足下綱後鰓目的成員。然而，在較新的2005年布歇特和洛克羅伊的腹足類分類，the families Umbraculidae and Tylodinidae belong to the superfamily Umbraculoidea Dall（英语：W.H. Dall）, 1889, part of the clade Umbraculida. Grande et al. (2004) found Umbraculoidea to be a sister clade to the Cephalaspidea (Acteonoidea excluded).[3]
The families Tylodinidae（英语：Tylodinidae） and Umbraculidae（英语：Umbraculidae） have large limpet-like external shells and a small mantle, while the species in the family Pleurobranchidae have a prominent mantle and an internal shell that becomes reduced or is lost in adults.[4] Many species produce mantle secretions as a chemical defense against predators [5]
^ 1.01.1WoRMS. Notaspidea. World Register of Marine Species. 2014 [2018-03-20].
^ 2.02.1WoRMS - World Register of Marine Species - Notaspidea. www.marinespecies.org. [2018-04-04]（英语）.
^Grande C.; J. Templado; J.L. Cervera; R. Zardoya. Phylogenetic relationships among Opisthobranchia (Mollusca, Gastropoda) based on mitochondrial cox1, tmV, and rmL genes. Molecular Phylogenetics and Evolution. 2004, 33 (2): 378–388. PMID 15336672. doi:10.1016/j.ympev.2004.06.008.
^R. Willan. Phylogenetic systematics of the Notaspidea (Opisthobranchia) with a reappraisal of families and genera. Am. Malacol. Bull. 1987, 5: 215–241.
^Aldo Spinella; Ernesto Mollo; Enrico Trivellone; Guido Cimino. Testudinariol A and B, two unusual triterpenoids from the skin and the mucus of the marine mollusc Pleurobrancus testudinarius.. Tetrahedron. December 1997, 53 (49): 16891–16896. doi:10.1016/S0040-4020(97)10124-7.
參考文獻
Notaspidea. Integrated Taxonomic Information System （英语）.
Powell A. W. B.（英语：Arthur William Baden Powell）, New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
Place in Moyen-Ogooué, Gabon Lambaréné Street in Lambaréné Lambaréné Location in Gabon Coordinates: 0°41′18″S 10°13′55″E / 0.68833°S 10.23194°E / -0.68833; 10.23194 Coordinates: 0°41′18″S 10°13′55″E / 0.68833°S 10.23194°E / -0.68833; 10.23194 Country Gabon Province Moyen-Ogooué Population (2013 census) • Total 38,775 Lambaréné is a town and the capital of Moyen-Ogooué in Gabon. With a population of 38,775 as of 2013, it is located 75 kilometres south of the equator. Lambaréné is based in the Central African Rainforest at the river Ogooué. This river divides the city into 3 districts: Rive Gauche, Ile Lambaréné and Rive Droite. The Albert Schweitzer Hospital and the districts Adouma and Abongo are located on Rive Droite. The districts Atongowanga, Sahoty, Dakar, Grand Village, Château, Lalala and Bordamur build the Ile Lambaréné. The majority of the people in Lambaréné live in the district Isaac located on Rive Gauche. This distr...
This article is about the number. For the year, see 800. For other uses, see 800 (disambiguation). Natural number ← 799 800 801 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 → Cardinal eight hundred Ordinal 800th (eight hundredth) Factorization 2 5 × 5 2 Greek numeral Ω´ Roman numeral DCCC Binary 1100100000 2 Ternary 1002122 3 Quaternary 30200 4 Quinary 11200 5 Senary 3412 6 Octal 1440 8 Duodecimal 568 12 Hexadecimal 320 16 Vigesimal 200 20 Base 36 M8 36 800 ( eight hundred ) is the natural number following 799 and preceding 801. It is the sum of four consecutive primes (193 + 197 + 199 + 211). It is a Harshad number. Contents 1 Integers from 801 to 899 1.1 800s 1.2 810s 1.3 820s 1.4 830s 1.5 840s 1.6 850s 1.7 860s 1.8 870s 1.9 880s 1.10 890s 2 References Integers from 801 to 899 800s Main article: 801...
"J57" redirects here. For the music artist, see J57 (rapper). J57 / JT3C YJ57-P-3 cut-away demonstrator at USAF Museum Type Turbojet National origin United States Manufacturer Pratt & Whitney First run 1950 Major applications Boeing 707 Boeing B-52 Stratofortress Boeing KC-135 Stratotanker Douglas DC-8 North American F-100 Super Sabre Vought F-8 Crusader Number built 21,170 built Developed from Pratt & Whitney XT45 Variants JT3D/TF33 Developed into Pratt & Whitney J52/JT8A Pratt & Whitney J75/JT4A The Pratt & Whitney J57 (company designation: JT3C ) is an axial-flow turbojet engine developed by Pratt & Whitney in the early 1950s. The J57 (first run January 1950 [1] ) was the first 10,000 lbf (45 kN) thrust class engine in the United States. The J57/JT3C was developed into the J75/JT4A turbojet, JT3D/TF33 turbofan and the PT5/T57 turboprop. [2] Contents 1 Design an...
