THE STARFISHES OF THE HAWAIIAN ISLANDS. 
1021 
from off the south coast of Oahu). When the membranous investment is removed from any of the 
spines they are seen to be delicate, slender, and pointed. 
External to each adambulacral plate is a small intermediate plate (or a transverse series of 2, 3, or 
more), the longitudinal series of which extends along the ray to about the fortieth adambulacral, and 
thirty-sixth inferomarginal plate. This series is a continuation of the small roundish or elliptical plates 
covering the actinal interradial area. The number of intermediate plates opposite each adambulacral 
and extending interradially, or transversely to the corresponding inferomarginal, is as follows: One 
small unpaired interradial intermediate plate adjacent to outer end of mouth plates; first adambulacral, 
4 (the series not reaching as far as inferomarginals); second and third adambulacral, 7 (series meeting 
first inferomarginal; fourth and fifth, 4 or 5; sixth, 4; seventh to fourteenth, 3; fifteenth to twenty- 
fourth, 2; twenty-fifth to fortieth, 1. In young specimens these plates are naturally fewer in number. 
New plates are added adjacent to the inferomarginals. The armature consists of small, blunt papilli- 
form spinelets, grouped or arranged in a double, longitudinal series. They are similar but slightly 
smaller than adjacent spinelets of the adambulacral plates. All are characterized by a soft membranous 
investment or sheath. 
Mouth or dental plates fairly prominent actinally; narrowly ovoid; rather elongate with a regular 
armature, consisting of a single line of stout, slightly flattened spinelets with rounded or trun- 
cate tips, arranged along margin of plate adjacent to the interradial suture. On miter free margin 
of plate, placed higher than the first series, is a second series of smaller, truncate, flattened spinelets, 
closely appressed to the outer side of the superficial series. Innermost spines of the superficial series 
stouter, longer, and more flattened than the rest, forming at each mouth angle two prominent teeth, 
with which are also associated two smaller spines of the second series. There is considerable variation 
in the relative size of these 4 teeth, but the lateral are much smaller and weaker than the median 
pair. They are usually directed away from the actinostome, appressed against the adjacent spines of 
their respective series, and are hence very inconspicuous. Space between the superficial series of 
companion plates fairly wide. 
Madreporic body small, situated near margin, about two-thirds the distance from center of disk to 
inner edge of the superomarginal plates. Striations coarse in adult individuals, beset with scattered 
tubercular projections; the latter often nearly absent. 
Color in life: Abactinal paxiliar areas brick red on the disk, shading into vinaceous rufous on 
arms, and finally to orange rufous at extremity of arms; superomarginal plates pinkish buff, shading 
into pink on the actinal surface; tube-feet raw sienna. Young individuals pinkish; marginal plates 
nearly white. Color in alcohol deep brown to dirty yellowish white; young, bleached yellowish. 
Variations: With one exception, most of the variations are of a very minor nature, and can easily 
be accounted for by the difference of size or age. There is, however, a group of specimens from off 
Diamond Head on the south coast of Oahu Island which have already been alluded to in the foregoing 
description; all these specimens are characterized by shorter and thicker rays (as compared with the 
disk) than those possessed by the type, and the paxillse seem to be just a trifle larger and are more 
crowded, giving the paxiliar area a more compact appearance; the spinelets of the marginal plates are 
fleshier and more squamiform. This form can be separated at once from the typical specimens 
throughout all the stages of growth, as shown in the accompanying figures. (PI. xlix, figs. 2 and 3.) 
None of the thick-rayed form were taken among the 150 specimens from off West Maui and the 
Pailolo Channel, but two apparently (almost) typical specimens were taken off Diamond Head, in the 
same general locality as the thick-rayed variety. The latter appears too slightly and insecurely sepa- 
rated from the typical form to warrant a specific name. Neither is it possible to bestow a trinomial 
designation upon “this well-marked ‘variety’ ” as some recent writers might be willing to do. Until 
something more definite is known concerning the different phases or variations (often quite constant 
and occurring in the same locality) which starfishes are known to exhibit, it seems somewhat ill- 
advised to pervert the trinomial to such uses. These forms can not be considered as subspecies, at 
least not in the sense in which ornithologists understand the term, for they are not equivalent to 
geographical races. 
Young stages: The young are considerably different in general appearance from the adult. The 
smallest specimen has R=9 mm., and r=3 mm. The smallest of the thick-rayed variety has R=9 mm., 
and r=4 mm. The small specimens are therefore characterized by shorter and broader rays than the 
adult, few marginal plates, relatively large ocular plates, which bear 3 minute spinelets, less compact 
