Aspidisca (aspidiska)

[NL., insects. Aspidiscidæ (as-pi-dis'i-dē), n. pl. [NL., Aspidisca , 1, + -ida .] A family of hypo tri cho us Ciliata. Aspidium (as-pid'i-um), n. [NL., ασπίς (άσπιδ-), a shield.] 1. A genus of ferns variously limited, but in its broad sense including all those in which the dot-like sori are covered by a roundish, peltate, or reniform indusium. Those with a reniform in dusium, attached by the sinus, are often separated as the genus Nephrodium , When the indusium is abortive or obliterated, the species are not distinguishable from forms of Poly podium. The genus is cosmopolitan, including nearly 300 species, which vary greatly in size, texture, venation, and division of the fronds. About 40 species are found within the United States. The common species are usually known as wood-ferns or shield-ferns. See shield-fern. 2. A genus of hymenopterous insects. Also Aspidion.