from Japan and the Indian Ocean. 87 



plate and only small tubercles on the rest of the plate. The 

 anibulncral ph\tes carry no large tubeicles. The abactiiial 

 side differs rather strikingly from that of tlie type (Chall. 

 Ecli. pi. xix, h. tig. 2j, there being a distinct primary tubjrcle 

 on every second interambulacral plate, forming a conspicuous 

 regular vertical series. The membranous interstices between 

 the plates are distinct ; the plates are not obliquely 

 directed, as in the type, but quite regularly horizontal. The 

 same holds good for the ambulacral plates, which have only 

 a few larger tubercles. The pores are arranged as in the 

 type specimen of tesseUatum. The differences in tlie test, 

 together with that in the pedicellaria:', would not seem to 

 justify de Meijere's view that it is a young A. tesseUatum. 

 However, as I have no material of this species, I do not 

 venture to pronounce a definite opinion, but shall be content 

 with giving the above particulars of tlie specimen in question. 



2. Asthenosown t'jimai, Yosiiiwara. 

 (PI. III. figs. 1,2; PI. V. Hgs. 1-3, 10, 12-14.) 



Astliejiosoma ijiinai, Yosiiiwara, 1897, " On Two new Species of 

 Adhcnoso7nu from the Sea of Sagami," Ani^otationes Zool. Japoii. i. 

 p. 8, pi. ii. tigs. 8-12. 



The four specimens before me agree very well with the 

 description given by Yoshiuara. Figiu-es are here given of 

 the species from photographs, the figures given by Yosiiiwara 

 being rather unsatisfactoiy. Otherwise 1 need not add 

 anything to the description of the structure of the test, except 

 of the niadreporic plate. According to Yoshiwara it is 

 " divided into four separate pieces of unequal size, the largest 

 occupying the normal position," a feature whicii he thinks 

 is merely an individual abnormality. It cannot properly be 

 said that the niadreporic plate is divided; it is the inadreporic 

 pores which have spread over the neighbouring platjs, a 

 feature known also in A. varium (Doderlein and de Loriol), 

 and upon the wliole not very seldom occurring among Echinids. 

 It is seen in all the four specimens, and must thus certainly be 

 regarded as a normal feature. 



Uf the i^edicellarite, Yosiiiwara only says he lias found two 

 kinds, '* one large and long-headed, the other small, long- 

 stemmed, and tritid^^ ; no figures are given. As in the other 

 species oi' Asthtnosoina, only tridentate and triphyllous pedi- 

 cellarite occur. Of the tridentute ones I find only two forms, 

 corresponding,- to the lar<>;er and smaller form of the other 

 species of this genus (comp. ' Ingolt ' Echinoidea, p. 49). In 

 the larger form (PL V. figs. 2, 12) (head up to 2'2 mm.) 



