Rotifera, Part 3: The Notommatidae (Monogononta) and the Scaridiidae (Monogononta)

Notommatidae is probably the most difficult family among all monogonont rotifers, and also comprises some of the genera possessing the largest number of species (e.g., about 190 species of Cephalodella are reviewed here). A confusing superfial phenotypic similarity exists among and within genera, thus misidentification is a very real danger. There are many species which have never been observed since their description, such as many of the North American acidophilic species reported by Harring and Myers, and by Myers.

The identification keys provided follow classical patterns, but synonymy and species relafionships have been examined with methods of numerical taxonomy, using the NTSYS-pc package of computer programs written by F.J. Rohlf. Unfortunately, a multiple entry key proved to grow unmanageably cumbersome in some species-rich taxa (e.g., Cephalodella). Here only a less desirable dichotomous key has been provided, even though it increases the danger of misidentification caused by even a single error in observation. In most cases both a mulfiple entry key and a dichotomous key have been supplied.

Proper identification requires perusal of the original literature, which contains more detail than can, by necessity, be provided in a taxonomy text. Therefore, we endeavoured to call attention to the most important additional sources pertaining to a species. This list is selective, rarely complete; old sources, obsolete or available only with difficulty are often omitted.