REPORT ON THE ASTEROIDEA. 295 
Remarks.—The group of species which I have classed in this genus form two very 
distinct sections, one of which may perhaps ultimately be considered worthy of being re- 
cognised as a subgenus, if it be not actually accorded generic rank. From the scantiness 
of the material now available, I have not, however, felt justified in taking this step at 
present, but merely indicate what seems to me may be the possible future requirement of 
the case when a more extensive series of specimens can be studied. 
Synopsis of the Species included in the Genus Nymphaster herein described. 
A. Supero-marginal plates separated throughout the ray by a median abactinal series of 
plates. Plates of the abactinal radial areas distinctly paxilliform. Entrenched 
pedicellariz present. 
a. Radial paxille with a large number of central granules. Rays comparatively 
long . ; : 3 : : ; ’ ; . 4 d , symbolicus. 
b. Radial paxillea with only two central granules, Rays comparatively short . bipunctus. 
B. Supero-marginal plates united in the median abactinal line throughout the ray. Plates 
of the abactinal radial areas very slightly tabulate. No entrenched pedi- 
cellariz present. 
a, Adambulacral armature with a secondary series of spinelets on the actinal sur- 
face of the plate . 5 : : ° ; ; , ; : : protentus. 
b. Adambulacral armature with no secondary series of spinelets ; granules only on 
the actinal surface of the plate. 
a. Radial paxille hexagonal; with pedicellaria . : , ‘ : basilicus. 
b. Radial paxille circular ; bearing no pedicellarie . : : : albidus. 
So far as I can judge from the information published, I am inclined to think that 
the following forms will ultimately be associated with the species I have placed in this 
genus, viz. Dorigona subspinosa, Perrier, Dorigona arenata, Perrier, Dorigona ternalis, 
Perrier, Dorigona prehensilis, Perrier, and Pentagonaster (Dorigona) moebii, Studer. 
Probably Pentagonaster alexandri, Perrier, may also be included in the same category ; 
and perhaps the form described under the name of Astrogoniwm fallax, Perrier, as well. 
Pentagonaster elongatus, Perrier, is another doubtful form, but from the description 
given appears to me to be more nearly related to one of the species I have placed in 
the genus Paragonaster, in which I venture to think it will ultimately be classed. 
Chorology of the Genus Nymphaster. 
a. Geographical distribution :— 
Atiantic: Three (or probably nine) species between the parallels of 40° N. and 
20° S. 
Nymphaster albidus, off the Cape Verde Islands. Mymphaster 
protentus, south-west of the Canary Islands. Nymphaster basilicus, 
off the west coast of Brazil. 
