ASTEROIDEA. 463 
Luidia fragilissima is more brittle in summer than in spring : Robertson, 
I. c. p. 36. 
Lepidaster [already employed for a fossil genus of Asteriidm by Forbes], 
g. n., Verrill, Tr. Conn. Ac. i. p. 577. Disk small, rays rounded, elongated j 
whole surface covered with a thin smooth skin, without granules or spines. 
Skeleton consists of the rays of several similar dorsal and lateral rows of rather 
large, more or less rhomboidal, overlapping plates, so articulated with those 
of the adjacent rows as to leave a regular row of pores between all the rows 
of plates, except between the ventral and ambulacral rows. On the disk, the 
plates are pentagonal. The interambulacral plates bear an inner row of small 
slender spines, several to each plate, bordering the ambulacral groove, and 
outside, but adjacent to these, a row of much larger oblong spines, not more 
than one to a plate. Type L. teres^ sp. n., id. 1. c.. La Paz. 
Lahidaster, g. n., Liitken, Vid. Medd. 1871, p. 289. Allied to Acanthaster^ 
Pycnopodittj and Pedicellaster. Arms numerous, 30 or more, slender, acumi- 
nate, almost serpentiform, brittle at base, annulated ; pedicellarise very nu- 
merous, placed crosswise ; madriporiform body single ; disk and terminal por- 
tion of the arms furnished above with scattered spines and straight pedicel- 
larifo. Ambulacral legs arranged in a double row. Type L. radiosus, sp. n., 
id. 1. c. p. 293, Patagonia. This species overthrows Perrier’s proposal to divide 
the Asteridce into two main divisions, viz. ; — those with crossed pedicellariae, 
either alone or accompanied with straight ones, and four rows of ambulacral 
feet ; and those with pincer-like and valvular pedicellariae, and two rows of 
ambulacral feet. 
Platasterias [preoccupied in Echin. by Blainville, 1830], g. n.. Gray, P. Z. S. 
1871, p. 136. Allied to Astropecten, but much flatter, and more like a deeply 
divided Palmipes ; no marginal tessera ; a single row of marginal spines. 
Type P. latiradiatus, sp. n., id, 1. c. pi. 9, Mexico (Tehuantepec). 
New species : — 
Asterias amurensiSf Liitken, Vid. Medd. 1871, p. 296, Ochotsk and coast of 
Amoorland. 
Echinaster tenuisjnnus, Verrill, Tr. Conn. Ac. i. p. 577, La Paz j E. cribellus, 
Liitken, I c. p. 288, Valparaiso (?=E. serpetdarim). 
Linckia nicobarica, Liitken, 1. c. p. 265, Nicobar (compared with L, laevi- 
gala, L.). 
Ophidiaster asperulm, p. 274, pi. 6. fig. 4, Viti, Fiji j granifeTf p. 276 ; cn- 
brarius, p. 277, Tonga : id. l.c. 
Scytaster subtilis, id. 1. c. p. 278, pi. 5. fig. 5, China Sea. 
Goniaster americanus, Charleston, S. C., africanm^ W. Africa : Verrill, Am. 
J. Sc. (3) ii. pp. 130, 191. 
Oreaster australis^ New Holland, pp. 262 & 263, hedemannij Billiton, pp. 
266 & 263, icestermanni^ Bengal, pp. 267 & 264, gracUisj N. Australia, pp. 260 
& 264 : Liitken, 1. c. 
Astfirina cabalisticay id. 1. c. p. 242, pi. 4. fig. 1, South Seas. 
Astropecten euryacanihus, Nicobar, p. 231, Java, p. 234 (with 
notes on its variation) : id. 1. c. 
Luidia brevispina, id. I, c. p. 228, Mazatlan. 
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