CLARK.] SALENIA BELLITLA. 43 



Salknia belli rL a Chirk. 

 Plate XI, Fig-.s. LVf-r/. 



Sahnia hell uJa Clar^, 189L Johus Hopkins ITiiiversity Circiilara, No. 87, p. 75. 



Deter miiiatlve characters. — Test small, compressed, circular; uj)per 

 surface convex; sides iutiated; under surface flat. Ambulacral areas 

 rather broad, nearly straight, with two lows of granules in each row; 

 poriferous zones broad, very slightly tiexed; pores round, unigem- 

 inal. luterambulacral areas wide. Apical disk convex and nearly 

 circular. ^loutL opening small. 



J)imeHsions. — Height, .^ inch; transverse diameter,'^,- inch. 



Description. — This Salenia is a very rare form, only a few specimens 

 having" come under the notice of the writer, yet from certain peculiari- 

 ties of outline ami structure it is not to be confounded with other species 

 heretofore described. 



In general outline the test is somewhat flattened; the ui^per surface 

 is regularly convex, the sides are inflated, the lower surface is flat or 

 slightly concave at the mouth opening*. 



The ambulacral areas are prominent and change but slightly in width 

 from the apical disk to the mouth edges. Two rows of maunnillated 

 granules, fifteen in each, occupy the center of each area. 



The luterambulacral areas are wide and consist of two rows of alter- 

 nating plates, five or six in each. The tubercles are prominent, but 

 decrease rapidly in size toward the mouth edges. The areola is of mod- 

 erate size, the boss narrow and indistinctly crenulate<l, and the mam- 

 elon small, flattened, and imperforate (PI. xi, Fig. 2g). An indistinct 

 circle of mammillated granules surrounds each tubercle. They unite to 

 form a sinuous double series between the rows of tubercles. Between 

 the larger granules are scattered irregularly numerous small granules 

 that are crowded together along the central line of the interambulacral 

 area (PI. XI, Fig. 2d). 



The apical disk is slightly convex, the anal opening interfering but 

 little with the regularity of the curved surface. The anal opening is 

 subcircular, with a flange-like rim. The plates are decorated with 

 oval grannies that are arranged in radial rows extending from the 

 opening of each genital plate and unite with corresponding rows of ad- 

 jacent plates at the suture (PI. xi, Fig. 2/). 



The mouth opening is small, being l)nt one-third of tln^ transverse 

 diameter of the test. Ten weak incisions divide the edges into lobes 

 that are nearly of equal size (PI. xi, Fig. 2h). 



Belated forms. — This species is quite distinct from Salenia te.rana or 

 8. tumidula, and at tlie same time does not admit of reference to any of 

 the European species. It is most closely related to 8. tumidula., but is 

 more compressed, lias a differently sha]>ed and decorated apical disk, 

 and has round and mammillated granules in the miliary space, while 

 those of ;8^. tumidula are characteristically oval. 



