| 词条 | Babella caelatior |
| 释义 |
| name = Babella caelatior | image = Babella caelata 001.png | image_caption = Apertural view of a shell of Babella caelatior | regnum = Animalia | phylum = Mollusca | classis = Gastropoda | unranked_superfamilia = clade Heterobranchia clade Euthyneura clade Panpulmonata | superfamilia = Pyramidelloidea | familia = Pyramidellidae | subfamilia = | genus = Babella | subgenus = | species = B. caelatior | binomial = Babella caelatior | binomial_authority = (Dall & Bartsch, 1906) | synonyms_ref = [1] | synonyms =Babella caelata (A. Adams, 1863) Parthenia caelata A. Adams, 1863 Pyrgulina (Egilina) caelata (A. Adams, 1863) Turbonilla caelatior Dall & Bartsch, 1906 (original combination) }} Babella caelatior is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies. The species is one of twelve in the gastropod genus Babella. DescriptionThe milk-white shell has an elongate-conic, turreted shape. Its length measures 4.4 mm. The three whorls of the protoconch are small, helicoid, rather loosely coiled and elevated. They have their axis at a right angle to the axis of the later whorls and about one-third immersed in the first of them. The nine whorls of the teleoconch are flattened, strongly sculptured, with axial ribs and three spiral keels. There is a strong, rounded, rather broad spiral keel on each side of the deeply sulcate periphery. The peripheral sulcus is about as wide as a keel and marks the path for the shouldered and crenulated summit of the succeeding whorls. A second deep spiral sulcus, equal in width to the peripheral one, is situated just posterior to the posterior keel, and this marks the anterior termination of the strong, rounded, backward-slanting axial ribs between the sutures. Sixteen of these ribs occur upon the second, seventeen upon the fifth, and twenty upon the penultimate whorl. The intercostal spaces almost as wide as the ribs, crossed by two strongly impressed, moderately broad spiral lines, which also pass over and somewhat constrict the axial ribs, giving them a dumbbell-shaped outline. The posterior thickened portion is a little wider than the anterior one. The space between these two deeply impressed lines is crossed by about eight minute, subequally spaced spiral striations. The periphery of the body whorl is deeply sulcate, crossed by numerous closely spaced axial striations. The keel anterior to the periphery is almost as strong as the one posterior to it. The third keel is a little anterior to the middle of the base and is rather low and broad. The space between it and the keel above is gently rounded and finely axially striated, which is also true of the space between this keel and the umbilical area. The aperture is moderately large, suboval, effuse at the junction of the outer lip and the columella. The posterior angle is obtuse. The outer lip is thin, irregular in outline, showing the external sculpture within. The columella is short, curved, stout, bearing a strong, acute, oblique fold a little anterior to its insertion. The parietal wall is covered by a thin callus.[2] DistributionThis species has only ever occurred within the Pacific Ocean off the east coast of Japan. References1. ^Bouchet, P.; Rosenberg, G. (2013). Babella caelatior (Dall & Bartsch, 1906). In: MolluscaBase (2017). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=588304 on 2018-01-08 2. ^{{cite journal | author = Dall W. H. & Bartsch P. | year = 1906 | date= | title = Notes on Japanese, Indo-Pacific and American Pyramidellidae | journal = Proceedings of the United States National Museum | volume = 30 | issue = 20 | pages = 347–348 | doi =10.5479/si.00963801.30-1452.321 }} External links{{commons category|Babella caelatior}}{{Taxonbar|from=Q4837709}} 2 : Pyramidellidae|Gastropods described in 1863 |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。