Prof. P, M. Duncan on the Salenidse. 63 



The actinostorae is contracted, small for the size of the 

 test, and smaller in extent than the apical system ; and the 

 cuts are very small. 



Each interambulacrum at the ambitus is at least four times 

 as broad as the ambulacrum in the same region, and the 

 median space is crowded with small secondaries and inter- 

 spersed granulations ; the largest of the secondaries cling to 

 the margins of the scrobicular circles of the great tubercles. 

 This crowding of small tubercles looking like large granules, 

 flat and broad, and not high or crenulate, and imperforate but 

 with distinct mamelon and boss, and without a " circle," the 

 base being flush with the test, gives a very marked appear- 

 ance to the test. Large and small secondaries and granula- 

 tions to the number of about 100 fill up the median space 

 flanked by the great primaries. The small granules are in 

 the midst. 



Each large primary has a wide plain boss, crenulate at the 

 shoulder, with fourteen minute tubercles in a circle. The ma- 

 melon is round, small, and imperforate. The base of the boss is 

 within a slightly elliptical scrobicule, which is below the level 

 of the median interambulacral space. The scrobicular-circle 

 edge has the largest of the small secondaries sparsely distributed 

 around it laterally. Above and below^ these are the sharp 

 eminences of neighbouring circles merging one into the other. 

 A few granulations are upon the edge here and there, and 

 especially on the side of the circles in contact with the ambu- 

 lacra, where the secondary tubercles are not well represented. 

 There is a slight circular ridge within the limits of the scro- 

 bicular circle as in the larger tubercles. 



Most of the mamelons are truncated cones ; but in the 

 younger specimens of the Salema they are sometimes rather 

 convex at the sides. 



The smaller primaries are slightly more convex in outline 

 than the others ; and their bosses are surrounded by a flat circle, 

 Their secondaries and granules in contact with the ambulacra! 

 margin are more decided and numerous than in the larger tuber- 

 cles. The small primaries are in two vertical and approaching 

 rows below the ambitus ; and the largest there is about the 

 size of the smallest primary close to the apical disk in some 

 interambulacra. The median interambulacral space is broad, 

 on a lower level than the ambulacra, and looks wavy to the 

 naked eye. On either side of it are the vertical series of the 

 five secondary tubercles on the scrobicular-circle edges, and in 

 the middle are two or sometimes three rows of small secon- 

 daries with granulations : these come down close to the 

 peristome ; and the lowest are just above the lowest smaller 



