based on the principle of Cephalization. 847 
in the inferior subdivisions of Worms), and the resemblance in 
the form of some species to Daphnize _ other Entomostracans, 
sustain the view that they are Crustace 
The Cirripeds appear to be only sttnebied: amplificate Ostra- 
coids. (See pages 324, 325.) 
he subdivisions of the orders of Insecteans and Crustaceans 
are then the following 
Insects. Spiders, Myriapods.; Decapods. /Tetradecap’s.| Entomostr. 
a. 
: | 
ve vihenams ood Scorpionoids.|Diplopods. Macrurans. | AmphipodsOstracoids, 
Apters, Acaroids. ? (Gastrarans Trilobites, ? | Limuloids, 
ma 3 2 — ea onions pec. pee 
Rotifers. 
T, Subdivisions of the orders of the class of Worms.—On the true 
method of prouping the typical (Branchiate and Abranchiate) 
Annelids, I here make no suggestions. The tribes of me other 
may possibly make a second subdivision of iis estideans. 
8. Subdivisions of the classes of Mollusks.—The ‘Orditary Mol- 
lusks include three orders, as usually given: (1) Cephalopods, 
(2) Cephalates and (8) Acephals ; of which, the first two corres- 
nd to different grades of typical Mollusks, and the last is 
egradational in its relations to the type, en she Sire being im- 
perfect in the senses and means of locomo 
The Ascidioid — comprise (1) Biochsopos and @) — 
cidians, with perhaps the Bryozoans as the third order. 
last, however, be ia a third class, si sagpested as one 
hesitation) on page 840, there is no third order, unless the i nfe- 
rior of the compound ’Ascidians, having w goer res to a 
group of individuals instead of to each one, and the oe 
Opening of each usually radiated (the snaitber of rays six), be re- 
garded as the ee This he et pane the jntenr () BLrachio- 
ig (2) Ascidians ; (8) Incrustates ; the first two typical, the 
ast degradational and akin ay shevighytatd. 
4. Conclusions. 
Ax, Jour. Sct.—Szconp Srrims, Vou. XXXVI, No. ae 1863. 
45 
B. Prosthenics or Araneoids, |Chilopods, Brachyurans, 'Isopods. Carcinoids, © 
.] 
