peristeropodous (peristeropodus)

Same as peristeropod. IMG:content-2722.png:[blocks in formation] (per-i-stō'ma-tä). [NL.: see peristome .] In zool ., a peristome, in any sense. peristomal (per'i-sto-mal), a. [ . pl . [NL., Gr. περί , around, + στόμα , the mouth.] 1. In Lamarck's cla ification, a family of trachelipod gastropods, having the aperture surrounded by a continuous lip or peristome, and including the genera Valvata , Paludina , and Ampullar i a , now di ociated in different families. Also Peri stomidæ.-2. [l. c.] Plural of per is tom a. peristomatic (per"i-sto-mat'ik), a. [ walls, framework, or skeleton: used chiefly of lower animals, as echinoderms, which have circular or radiate mouth-parts. Specifically-(a) The circumoral body-wall of an echinoderm; the peristomial perisoma: the opposite of periproct. See cut under As trophy ton. (b) In Crustacea, specifically, the space included between the pterygostomial plates and the antennary sternite. Milne - Edwards. (c) In the Infusoria, the region with its accompanying cilia or other circum oral appendages. In Vermes, the first true somite of a polychæto us annelid, coming next to the præstomium, and bearing the mouth. See præstomium. (e) In entom., the border of an insect's mouth, or properly the border of the mouth-cavity irrespective of the trophi. In insects having suctorial mouths, as the Diptera, the per is tomium is the border of the cavity from which the proboscis or sucking-organ projects. (f) In conch., the margin of the aperture of the shell when the outer and inner lips are united and surround the aperture. per is tomia, n. Plural of per is tomium .