STARFISHES OF THE PHILIPPINE SEAS. 



151 



virtually form chevrons pointing toward the center of disk, but the 

 apexes of the chevrons are not defined, because the regularity of the 

 plates is interrupted along the radial line, as is characteristically 

 the case in Dipsacaster. There are no means of comparing the form 

 of the mouth plates, which would probably give valuable data. 

 AVliile no record is made of the internal anatomy of magniflGus^ I 

 think there is little doubt that it is a typical Dipsacaster. 



LoncTiotaster forcipifer Sladen is based on what is probably an im- 

 mature specimen. L. tartareus is the first species mentioned, and 

 may serve as the genotype, since none was designated. The genus, as 

 based on tartareus^ appears to be a near relative of Dytaster. There 

 is a small spine on each marginal plate, and one on most of the actinal 

 intermediate plates. (See Sladen, 1889, pi. 16.) 



In this connection it might be well to state the characters which 

 differentiate D. sladeni and D. laetmophilus, two forms very similar 

 in general habit. I have compared specimens. 



D. JactmopMlus. 



Spinelets of inferomarginals flat- 

 tened and narrow - squamiform on 

 actinal surface, becoming rather 

 broadly squamiform on the plates of 

 proximal third of the ray. These 

 spinelets overlap and become larger 

 from the inner edge toward the am- 

 bitus. 



Raised ridge of inferomarginal 

 plates (at middle of ray) when de- 

 nuded has the breadth of the actinal 

 face 3 or a little over 3 times the 

 length of the inner end of this ridge, 

 while the outer end (that defining 

 ambitus) is bent slightly distad. 



Actinal intermediate plates vei*y 

 narrow in the interradial region, the 

 interradial dimension at least twice 

 the other, sometimes 3 or 3.5 ; the 

 fasciolar grooves separating these 

 plates are wide and clearly marked 

 (as wide as denuded tabulum of ad- 

 jacent plates). 



Central spinelets of actinal inter- 

 mediate plates decidedly thicker than 

 the peripheral in the interradial re- 

 gion, and somewhat squamiform and 

 appressed. 



Abactinal plates of lateral regions 

 of area roundish, not strongly lobed. 



D, sladeni. 



Spinelets of inferomarginals uni- 

 formly very slender and spiculifornis 

 on the actinal surface, except for a 

 few enlarged ones at outer end of 

 plate. 



The extreme breadth of the actinal 

 aspect of ridge is about 2 times the 

 length of the inner end, while the 

 outer end is not bent distad. 



Tabulum of actinal intermediate 

 plate not so compressed, and grooves 

 more or less masked by spinelets. 

 The actinal plates are fewer, but, in 

 proportion to width of inferomargi- 

 nals are larger. 



Central spinelets not thicker than 

 the peripheral, but slender and radi- 

 ating. 



Abactinal plates of lateral regions 

 of area strongly lobed, those of me- 

 dian radial region slightly scalloped. 



