200 NATUEAL HISTORY BULLETIN 



by wide grooves. The dorsal paxillae may be quadrate at surface 

 and crowded, in regular rows, or stellate. Regular rows of 

 papulae between the rows of paxillae. No superambulacral plates 

 observed. 



Gonads are multiple, in rows, with separate pores along the 

 sides of the rays. Papulae may be branched. Ambulacral am- 

 pullae are single. 



LuiDiA CLATHRATA (Say) Liitkeu. 



Asterms clatlirata Say, Journ. Acad. Nat. Sci., Philad., vol. v, p. 143, 1825. 



Luidia clatlirata Liitken, Vidensk. Meddel., p. 37, 1859. Gray, Synopsis, p. 

 4, 1866. A. Agassiz, North American Starfishes, p. 117, pi. xx, 1877, 

 (Structure.) Verrill, Notes on Kadiata, Trans. Conn. Acad., vol. i, p. 

 271, 1867 ; Amer. Journ. Science, vol. iii, p. 438, 1872 : ditto, vol. xlix, 

 p. 134, 1895 ; Trans. Conn. Acad. Sci., vol. xi, p. 36, 1901 (habits) ; 

 Starfishes of N. Pacific, pp. 7, 31, pi. 103, fig. 1, 1914a. 



Plate xxiv; figure 2. 



This is a large, five-rayed species, with long rays. 



The dorsal paxillary area of the rays is rather flat or some- 

 what convex, wide, covered with unusually large, mostly squar- 

 ish, or at least quadrangular, paxillae which form proximally, in 

 medium sized specimens, about ten to twelve nearly regular rows. 

 About four or fi\ e of the lateral rows, on each side, are decidedly 

 larger and more regular than the rest. The first three rows are 

 nearly equal; the others decrease regularly in size; the two or 

 three median rows are the smallest and least regular. On the 

 disk they become more crowded, and irregularly arranged ; many 

 are hexagonal, pentagonal, or polygonal ; those in the center are 

 the smaller and more irregular, being about equal in size to the 

 median ones of the rays. All the paxill^ are covered with nu- 

 merous rather coarse, short, nearly even-topped, but unequal, 

 spinules. On the larger lateral paxillae there are usually from 

 tw^elve to sixteen larger central spinules which are enlarged and 

 rounded at the tips, and stand in rows of three or four, while the 

 margins are bordered with numerous much smaller, slightly 

 clavate spinules. On the smaller median paxillae there are usual- 

 ly six to eight of the larger central spinules, surrounding one or 

 tw^o in the middle, thus often forming a minute rosette-form, 

 bordered by the finer marginal spinules. 



The inferomarginal plates are large ; each bears two unequal, 



