1156 General Notes. [November, 
with figures of nearly each genus, will prove very useful to 
American microscopists. After remarking upon and criticizing 
the systems of Ehrenberg, Dujardin, Leydig and 
offers one of his own. The class Rotifera falls, he thinks, into 
four natural orders, according to their modes of locomotion. 
“There are some that swim only; others that both swim and 
creep like a leech’; those that both swim and skip; and lastly, 
those that when adult are fixed; and these orders differ in the 
main from each other in the form and use of the foot, Ineach 
order, too, there are typical genera, round which the rest may be 
grouped, differing from each other in the shape of the trochal 
disc and the position of its ciliary wreaths, as also in the struc- 
ture of the manducatory organs, and sometimes in other impor- 
tant points as well.” : 
The form of the mouth-parts affords good family characteris- 
tics, while a difference in the shape and disposition of the troch 
disc and its ciliary wreaths generally accompanies a difference in 
the manducatory organs, the two together serving “as eae 
guides to a re-classification of the rotifers into families, W 
the author attempts to do. 
Dr. Hudson’s system is as follows : 
CLASS ROTIFERA. 
wrinkled, non-retrec- 
Order I. Ru1zoTa.—Fixed forms; foot attached, transversely j; Fam. 2 
tile, truncate. Family 1, losculariade (Floscularia, Stephin ae 
Melicertade (Melicerta, Limnias, CEcistes, Cephalosiphon, Lacin 
galotrocha, Conochilus), eg a 
Order II. BDELLOIDA.—That swim and creep like a leech ; pia = | 
telescopic, termination furcate. Fam. 3. Philodinade ( 
Callidina), Rhino); 
Order III. PLörMmA.—That only swim. Fam. 4. Hydatinade (Hya (Noton 
_ Fam. 5. Synchetade (Syncheta, Polyarthra) ; Fam. - Motomme Fam. 7. T 
mata, Diglena, Furcularia, Scaridium, Pleurotrocha, Distemma) ; Brock: 
P 
arthrade (Triarthra); Fam. 8. Asplanchnade (Asplanchna); Fam 9. (ie 
onide (Brachionus, Noteus, Anuræa, Sacculus); F Diplax, Mone 
11.. Euchlanide (Euchlanis, Salpina, “1P™ Dig- 
dina, Pompholyx) ; Fam. 
styla, Colurus, Monura, Metopidia, Stephanops, Monocerca, 
ocharis). aa 
Order IV. ScIRTOPODA.—That swim with their ciliary wreath, ar ee | 
of hollow limbs with internal locomotor muscles, Fam. 12. / 
alion), 
demy É 
Tue Nature or Ecuinoperms.—At the Paris Acade the 
