A Key to the Rotifera, for the Amateur. 
* A Key to the Rotifera was several years ago (1887), published by the late Dr. Thos. 
8. Stevens, and although inaccurate, was so useful to the beginner for whom it 
was exclusiveiy intended, thatit is here revised and enlarged by one of his friends 
with the same object exclusively in view. It is neither the desire nor the province 
of the editor to struggle with the synonymy or to correct errors of observation. It 
is said that Gosse misinterpreted the structure of Ceelopus, and that the genus has 
no rightful existence, but the Key follows Gosse, and the references are chiefly to 
Hudson and Gosse’s Monograph, and its Supplement, with a few exceptions. ‘‘J’’ 
directs to the “Journal of the Royal Microscopical Society ;” “Q” to the ‘Journal of 
the Quekett Microscopical Club,” with year and page: ‘“‘Weber” to ‘“‘Faune Rota- 
torienne du Bassin du Leman,” par E,-F, Weber. The number appended to each 
Genus in the Key to the Genera, is the number preceding that Genus in the Key to 
the Species. The editor repeats that the only object of the paper is to help the be- 
ginner in his desire for mental recreation : it has no value to those making profession 
al researches.—H. 8, M, 
GENERA. , 
Corona subcircular or broadly oval, (*) 
Corona prodticed into lobes, (**) 
Corona cup-like, (***) 
§§ Clusters fixed ; tubes gelatinous, cohering; corona cordate 
se bara acdpesstcras susasauigr'o abe veanpoeeioyuboa dere Lacinularia, 9 
§§ Clusters fixed, without tubes ; corona reniform...Megalotrocha, 10 
§§§ Free-swimming, creeping like a leech ; foot wholly telescopic, ([]) 
§S$ Free-swimming and sometimes creeping by the toes, (c) 
§$§ Free-swimming and skipping by 6 limbs ~.aepedalion, 65 
§§§ Free-swimming only ; cilia equatorial ; body spherical 
BMA INR OR OU MEL ae STE BARN TM El Trochosphera, 11 
* With 2 hooks enclosing the dorsal antenna........ Cephalosiphon, 70 
"| Aquatic (a few marine), (A). 
"| Marine, adherent. Ectoparasitic, (B). 
A Permanantly adherent, not in social clusters but sometimes 
in family groups, (§) 
A Permanently adherent in social clusters, (§ §) . 
A Free-swimming, solitary, (§ § §) 
A Free-swimming ‘in clusters; tubes cohering, gelatinous 
i ae ; MRR LN MeN OOM Conochilus, 12 
B Head and neck distinct ; adherent by 1 foot-disc............ Seison, 70 
Be Giscce mead and neck*> ,,~ 6 55. oy io aces Discopus, 66 
B Adherent by 2 pedunculate discs Saccobdella, 72 
B Adherent by hemispherical denticulate foot........... Paraseison; 71 
§ 
§ 
5 
* With 2 dorsal hooks, but dorsal antenna absent ............. CG cistes, 8 
* Without dorsal hooks; foot present; in a tube or not,....icistes, 8 
** Lobes 8, not setigerous ; in gelatinous tube................ Octotrocha, 80 
** Lobes 5, long, slender, erect, convergent... Stephanoceros, 4 
** Lobes 4, not setigerous ; inhabiting a tube... Melicerta, 5 
** Lobes 2—7, setigerous ; setz long, radiating............. Floscularia, 1 
** Lobes 2, not setigerous ; tube usually membranous........ Limnias, 6 
