ASTPROIDFA. 19 
Asteroidea (pars), Burmeister, Hdbh. Natwrg. (1837) p. 467. 
Asteroidea, Wright, Mon. Brit. Foss, Echin. Oolit, 11. (1863) p. 1; Nor- 
man, Ann. §& Mag. xv. (1865) p. 115; Perr. Arch. Zool. expér. iv. 
(1875) p. 281; Fewkes, Proc. Bost. Soc. N. H. xxiv. (1889) p. 96; 
Sladen, Chall. Rep, Ast. (1889) p. xxviii; Bell, Ann. § Mag. viii. 
(1891) p. 214; [mon Zettel, in Hdbuch. Pal. (1879) |. 
Stelleride, Zittel, Hdbuch. Pal, (1879) p. 447. 
Tocastra+Colastra+ Brisingastra, Haeckel, Gen. Morph. ii. (1866) 
pp. Ixv & lxvi. 
On the movements of Asteroidea, see Preyer, MT. zool. Stat. Neap. vii. 
(1886 & 87) pp. 33 & 77; on their anatomy see Cuénot, Arch. Zool. expér, 
v. Suppl. art. 2 (1887-90). 
The Asteroidea are caliculate, actinogonidial, eleutherozoic, azy- 
gopodous Echinoderms, in which there is an open ambulacral groove. 
The stellate form of the body is often well marked and the rays 
prolonged into ‘‘ arms,” which vary in their proportional length to 
the diameter of the disk; the digestive system, which is rarely 
aproctous, and the generative share in the stellate disposition of the 
organism. Pentameric repetition is more often exceeded in this 
than in any other class ; and asexual reproduction from a part of 
the body is by no means uncommon ; respiration diffuse. 
Order 1. PHANEROZONIA. 
Phanerozonia, Sladen, Chall. Rep. Ast. (1889) p. xxviii. 
Asteroidea with well developed marginal plates in two distinct 
rows; the superior and inferior touch, and usually have their axes 
in parallel planes. Papule confined within the area bounded at the 
sides by the superomarginals. Ambulacral plates not crowded 
nor narrow. Adambulacral plates take a prominent share in the 
formation of the oral plates. Pedicellariz valvate, foraminate or 
excavate. 
Family 1. ARCHASTERIDA. 
Archasteridee, Viguier, Arch. Zool. expér. vii. (1878) p. 235 ; sens. emend. 
Sladen, Chall. Rep. Ast. (1889) p. xxviii. 
Phanerozonia in which the calycinal plates are inconspicuous in 
the adult, the abactinal plates spiniform or paxilliform, and the 
integument spiny; there is an anus, no superambulacrals, large 
adambulacrals, and, usually, pedicellariz. 
Two subfamilies. 
Subfamily 1. PARARCHASTERIN 4. 
Pararchasterin, Sladen, Chall. Rep. Ast. (1889) p. xxviii. 
Archasteride with papule in a limited area only at the base of 
c2 
