24 ECHrNODERMA. 



l re Tribu, Duj. Sf Hup. Echin. (1862) p. 329. 



Typical Starfishes, Gray, Syn. B. M. 42nd ed. (1840) p. 61. 



Asteriidse (s. em.), Sladen, Chall. Rep. Ast. (1889) p. xxxix. 



The Asteriidse are cryptozonate Asteroids, with the reticular 

 abactinal skeleton made up of small unequal plates carrying one or 

 more small spines. The podia appear to be arranged in four rows. 

 Major and minor pedicellaria?, as a rule, both present. 



One genus : Asterias. 



Family 7. BRISINGIM1. 



Brisingidas, Sars, Remarkable Forms, ii. (1875) p. 101 ; Terrier, Nouv. 

 Arch. Mus. vi. (1884) p. 188 ; Sladen, Chall. Rep. Ast. (1889) p. xl. 



Cryptozonate Euasteroidea, in which the reduction of the marginal 

 plates is altogether or almost complete ; and the dorsal skeletal plates, 

 if present, found only on the disk and the proximal portion of the 

 arms ; no intermediate ventral plates or any interbrachial septa. 



Two genera : Brisinga and Odinia. 



Class X. OPHIUROIDEA. 



Ophiuva, Lamk. Syst. (1801) p. 350. 



Asterophidea, de Bl. Diet. Set. Nat. lx. (1830) p. 223: id. Actinol. 



(1834) p. 242. 

 Ophiures, Ac/ass. Mem. Soc. Neuch. i. (1836) p. 192: id. Ann. Sci. 



Nat. vii. (1837) p. 287. 

 Ophiurida, Gray, Syn. B. M. 42nd ed. (1840) p. 63 ; id. Brit. Bad. 



(1848) p. 23. 

 Ophiuridse, Forbes, Brit. Starf. (1840) pp. xiv, 19; M. Tr. Syst. Ast. 



(1842) pp. 79, 81 ; Bronn, Klass. u. Ordn. (1860) p. 283. 

 Ophiurse, Forbes, Mem. Wern. Soc. viii. (1839) p. 124 ; Dub. fy Kor. 



Vet. Akad. Hdlg. 1844 (1846) p. 233. 

 Ophiurides, Duj. $ Hup. Ech. (1862) p. 219. 

 Ophiuroidea, Norman, Ann. # Mag. xv. (1865) p. 104 ; Ljungman, 



CEfv. Vet. Akad, Forhlg. 1866 (1867), p. 303; Cuenot, Arch. Zool. 



exper. vi. (1888) p. 33 ; Bell, Ann. $ Mag. viii. (1891) p. 215. 



The Ophiuroidea are caliculate, actinogonidial, eleutherozoic, liss- 

 actinic Echinoderms in which there is no distinct ambulacral groove. 

 The " arms " are sharply marked off from the disk, are very rarely 

 more than five in number, and are sometimes elaborately branched. 

 The digestive system, which is aproctous, and the generative are 

 confined to the area of the disk, as is also the specialized respiratory 

 apparatus which, typically, takes the form of deep clefts. 



