ECHINODERMATA. 
327 
armed organs are present on all parts of the upper surface of the body. 
They can open and shut their arms, and resemble in some measure the 
pedicellariae of the sea-urchin : they are divided into two sorts, the pe- 
dicellarim forcipatas, with thin pointed arms, and pedicellariae valvulatae, 
with broad flap-like arms. The former are sometimes pedicled, some- 
times sessile ; the latter are always sessile. 
The Asterice are divided into three families ; the first comprehends 
those star-fishes which have four rows of tentacles in each abdominal 
furrow, and an anus ; to this belongs the single genus, Asteracanthion, 
with fourteen species, among which are three new, A. africanus, polaris, 
and hootes. The second embraces those genera which have only two rows 
of tentacles in the furrows and an anus ; it contains fourteen, viz., — Echi~ 
naster, with eleven species, of which E. crassus, gracilis, Eschrichtii, 
Miill. and Trosch., eridanella, and serpentarius, Val., were previously 
undescribed : Solaster, Forb., with two species : Chcetaster, with three 
species, among which are the two new species, Ch. Hermanni, M. and T., 
and Troschelii, Val. : Ophidiaster, Ag., with twelve species, among which, 
O. Hemprichii, diplax, Ehrenbergii, tuherculatus, echimdatus, M. and 
T., and Ornithopus, Val., are new : Scy taster, with six species, among 
which, S. zodiacalis, semiregularis, and Kuhlii, are new : Culcita, with 
four species, of which, C. novce-guineoe, and grex, are also new : Aste- 
riscus, with fifteen species, among which, A.pectenifer, Diesingi, M. and 
T., cepheus and setaceus, Val., are new: Pteraster, with one species: 
Oreaster, with seventeen species, among which, 0. ajinis, chinensis, 
tuherculatus, verrucosus, carinatus, orientalis, M. and T., and regulus, 
Val., are new : Astrogoniwm, with ten species, which contain A. magni- 
ficum, astrologorum, ornatum, Lamarcldi, M. and T., and geometricum, 
as new : Gonidiscus, with nine species, two of which are new : G. pla- 
centa, and capella, M. and T. : Stellaster, with two species : Aster opsis, 
with four species, among which, the only undescribed species is A. ctena- 
cantha, Val. : and, finally. Archaster, with three species. The third 
family contains those star-fishes, which are furnished with two rows of 
tentacles on the abdominal furrows and no anus ; to this belong only 
three genera ; Astropecten, with twenty-five species, of which, A. hrasi- 
liensis, Valenciennii, Tiedemanni, polyacanthus, armatus, Hemprichii, 
japonicus, hispidus, longispinus, marginatus, andromeda, granulatus, 
M. and T., scoparius, serratus, and hystrix, Val., have been hitherto 
undescfibed : Ctenodiscus, with two species : and Luidia, with three 
species, of which L. maculata, M. and T., is quite new. The generic cha- 
racters of all these are chiefly taken from the form of the arms, whether 
they are long or short, cylindrical or conical ; and from the covering of 
the upper surface of the body, whether covered with plates, spines, pro- 
cesses, granules, tubercles, pedicellariae, &c. ; and after the manner in 
which the different parts are arranged. 
The section of the Ophiuridce,, which want the pedicellaria? and the 
371 
