SHALLOW- WATER STARFISHES 309 



Pedicellariae often lacking; when present, usually bivalve, some- 

 times spatulate and excavate or fossate. Superambulacral plates 

 often present. 



Genus Linckia Nardo. 



Linckia NARDO, Oken's Isis, 1834, p. 717. Gray, op. cit., 1840, p. 284; System, 

 p. 13, 1866. Verrill, op. cit., 1867, p. 285. Sladen, op. cit., 1859. Fisher, 

 op. cit, 191 ib, p. 242. 



Ophidiaster (pars) MULLER and TROSCHEL, Syst., p. 28, 1842. 



Phataria MONKS, op. cit., 1903, p. 35 (non Gray). 



Disk small, rays long, slender, nearly terete, usually variable in 

 number. Some species are autotomous. Adambulacral plates bear 

 granule-like structures, in two series. Papulae lacking on actinal side, 

 numerous in abactinal areas. Abactinal plates irregularly arranged. 

 Pedicellariae not observed. 



LINCKIA COLUMBIA Gray. 



Linckia Columbia GRAY, op. cit., 1840, p. 285 ; Synopsis, 1866, p. 14. Sladen, 



op. cit., 1889, p. 784. Verrill, op. cit., 1867, pp. 332-334. Fisher, op. cit., 



191 1 b, p. 242, pi. XLVIII, figs. 1-7. 

 Linckia diplax PERRIER, Revision Stell., p. 144, 1875. 

 Phataria (Linckia} fascialis MONKS, op. cit., 1903, LV, p. 351 (autotomy and 



variations). 

 Phataria (Linckia) unifascialis, var. bifascialis MONKS (non Gray) ; op. cit., 



1904, LVI, p. 596, pi. XLII (autotomy, variations, etc.). 



This species is probably not to be found within the proper bounds 

 of this report. It is introduced chiefly because of the great interest 

 connected with the remarkable variability, autotomy, powers of 

 restitution of lost rays, or even of the entire body, from a part of one 

 ray, etc., which have been so well and carefully studied and 

 described by Miss Sarah Monks, in the works cited above. 



Other species of the genus share these peculiarities, for example 

 L. guildingii, which I have studied in Bermuda. 



Miss Monks, op. cit., 1904 (pp. 596-600), has shown that this 

 species is very variable in number of rays, madreporites, etc. The 

 variations in number of rays are mostly due to autotomy and irregu- 

 lar restoration of rays, so that there may be from five to eleven rays. 

 Though five is the normal number, regularly six-rayed specimens 

 are common. 



She found many in the " comet-form " and succeeded in producing 

 such forms by cutting off rays at some distance from the disk. 

 These, in the course of six months, produced a " comet-form " with 

 a new disk. 



