298 On Young Specimens o/Antlienea sp. 



having tliree ; in some tliey have become fused togetliev and 

 elongated. The tubercles themselves are not granulated, but 

 are developed from the granules, and on some of the ))lates 

 the process may be seen in various stages of development. 

 At the interbrachial arc the plates are wedge-shaped, 3 mm. 

 broad and 4 mm. long, but distally they become broader and 

 square. The terminal plate is small, being about the size of 

 the last paired marginal. Further, it is granulated and may 

 have tubercles. 



The infero-marginal plates approximate to tlie supero- 

 marginals, but continue on to the actinal surface also, and 

 are well-defined ; the change in shape distally is well illus- 

 trated in both specimens. The granulations are more regular 

 than on the upper series. On tlie second plate, counting 

 from the interbrachial arc, tubercles begin to develop and 

 increase in size and number toward the distal end of the arm ; 

 but they are not nearly so prominent as those on the supero- 

 marginal plates. There are no pedicellarise on the marginal 

 phites. 



The niadreporite, which occupies an interradial position, 

 measures 2 mm. ; it is lozenge-siiaped and coarsely striated ; 

 the strife radiate centrit'ugally, very little convolution being- 

 noticeable. It is surrounded by a ring of evenly placed 

 granules. 



The specimens are undoubtedly young examples, and 

 correspond in some respects to the description of Anthenea sp. 

 descril)ed by Simpson and Brown (i), and also have certain 

 affinities with SiraUer tuberculatus described hy Clark (2). 

 But the differences are so marked that it is not possible to 

 accept Clark's very full generic and specific diagnosis as 

 applicable to the present specimens. Koehler (3) gives a 

 veiy short account and a figure ol Anthenea sp., juv. ; but he 

 does not refer to the ambulacral region^ the description of 

 which is essential to a correct identification of the specimens. 

 The absence of tubercles from the centro-radial plates and 

 from the supero-marginals are points wherein Kcehler's 

 specimens differ from those above described. 



Literature. 



(i) Simpson, J. J., and Brown, li. N. Rudmose. 1900. " Asteroidea 

 of Portiifjuese East Africa." Proc. R. Pliys, Soc. Edinburgli, 

 xviii. (1910-1912) p. 60. 



(2) Clauk', H. L. 1915. "The Echiuoderms of Ceylou, other than 



Holothurians." Spoha Zeylanica, x. pt. 37 (191.5), p. 80. 



(3) KcEHi.EH, It. 1910. "An Account of the Shallow-water Aate- 



roidea." Echiuoderuia of the Indian OceaU; pt. vi. p. 91, pi. xvi. 

 tisi-. 1. 



