Ardeadoris egretta Rudman, 1984 - GBIF.

Classification of Molluscs: Classification in Outline (Up to Orders): The classificatory scheme followed in the present text is based largely on the plan laid down by E.E. Ruppert and R.D. Barnes (1994) in their book “Invertebrate Zoology”.

The phylogenetic position of the polar nudibranch genus Doridoxa within Nudibranchia is controversial. Because Doridoxa is only found in polar deep waters specimens available for research are scarce.

In total we aligned sequences of 56 taxa (Table 1) for the large taxon set and 34 taxa for the reduced taxon set.Due to ambiguous homologisation of certain nucleotide positions in the alignments we excluded parts of high variability which were mainly due to inserts in certain taxa from the alignments.

Huxley in 1880 briefly suggested the arboreal origin, or primordial treehabitat of all the marsupials, a suggestion abundantly confirmed by the detailed studies of Dollo and of Bensley, according to which we may imagine the marsupials to have passed through (r) a former terrestrial phase, followed by (2) a primary arboreal phase - illustrated in the tree phalangers - followed by (3) a.

Classification Species dactylomela Genus Aplysia Family Aplysiidae Suborder Aplysiomorpha Order Opisthobranchia Class Gastropoda Phylum Mollusca Kingdom Animalia; Size Range 20 cm; There are several sea hare species in the Sydney region. Sometimes reaching 20 cm, these large sea slugs may be difficult to spot at first as they are well camouflaged.

Diacavolinia longirostris (De Blainville, 1821a) Overview This is a medium sized, uncoiled thecosomatous pteropod, 0.7 cm long. It has a flat dorsal side with moderately developed ribs.The ventral side is vaulted. The caudal spine is absent and a caudal spine mark is not left as the ventral and dorsal sides grow together. The lateral spines are well developed.

Introduction: The problem of homology. The concept of homology has long been implicitly used by biologists, as comparison has been the basis of our classification of the natural world at least since Aristotle (Russell, 1916; Nordenskiold, 1928).Nevertheless, the study of structural correspondence moved to the foreground (Russell, 1916; Coleman, 1971) in the first half of the nineteenth century.

A few gastropod types (such as conch, abalone, limpets, and whelks) are used as food, and several different species may be used in the preparation of escargot. Very few gastropod species transmit animal diseases; however, the flukes that cause human schistosomiasis use gastropods as intermediate hosts.

Limacina (Thilea) lesueuri d'Orbigny, 1836 Overview This is a small, shelled, pelagic thecosomatous pteropod with a left-coiled shell, 0.1 cm in diameter.The spire is depressed, the body whorl increases very quickly in diameter. It has 4.5 colourless, transparent whorls.There is a narrow but deep umbilicus, spiral striation is found around the umbilicus and the remaining parts the shell are.

The cups are placed symmetrically on the end of the arms, and it is easy to see that the wind always has the hollow of one cup presented to it; the back of the cup on the opposite end of the cross also faces the wind, but the pressure on it is naturally less, and hence a continual rotation is produced; each cup in turn as it comes round providing the necessary force.

Haminoeidae is the most diverse family of Cephalaspidea with 13 to 17 genera commonly recognised as valid and with 46 genera that historically have been moved back and forth between Haminoeidae and other families. Due to poor definition of most genera the family is plagued by extensive taxonomic confusion and its generic composition and internal relationships remain uncertain. In this work we.

Bibliography of Opisthobranchia 1554-2000 Steven J. Long (assisted by Gary McDonald). This bibliography has been in preparation since 1967 (about the same time the Western Society of Malacologists was formed). It owes its existence to many dozen people who have encouraged me and helped me with the literature. Gary.