306 BULLETIN OF THE BUREAU OF FISHERIES. 



Family GONIASTERID^ Forbes, 1840 (restr.). 



Subfamily < !< >NIASTERINJ2 Verrill, 1899. 

 Genus TOSIA Gray. 

 Tbsia Gray, Ann. N. H., VI, 1810, 281 i T. ausiinli* dray). 



Tosia leptocerama, new species. 



Pentagonal. E = 63 mm.; r = 44 mm. R = 1.43 r. In smaller examples (e. g., R = 38 mm.; 

 r = 22 mm.) the contour is often stellato-pentagonoid, R equaling 1.73 r; but usually the form is 

 pentagonal. 



Disk remarkably thin for the genus, the marginal plates being small, elongate, and inconspicuous; 

 sides of body only 3.5 mm. high; edges of <lisk curved inward gently toward the interradius; supero- 

 marginals not in contact at tips of "rays;" radial areas of abactinal surface and center of disk some- 

 what inflated; actinal area subplane, or sunken, making the inferomarginals appear as a narrow ridge, 

 the body being not more than 1.5 mm. thick in the median interradial area. 



Marginal plates elongate and, owing to the thinness of the disk, rather small; except for the first 

 2 or .'! plates, the members of the 2 series alternate. Superomarginals, 14 in number from each inter- 

 radial line to extremity of series, or 28 to each side of disk, about as high as broad, and much longer 

 than high, except at the end of the series, where they are shorter; these plates forming a narrow 

 border to the abactinal area and covered with a rather uniform, dense, polygonal granulation, a 

 peripheral series being readily distinguishable; the outer plates with a small naked area on abactinal 

 face, bearing 1 to S small. 2-jawed pedicellarise, larger than the granules; these pedieellaria 1 present 

 also on the inner plates, but there only a narrow area about each is left free by the granules; lower 

 margin of each superomarginal angular. Inferomarginals Hi to the ray or 32 to a side, and much 

 wider than high, encroaching farther upon actinal area than do the dorsal series upon the abactinal; 

 in the middle of the actinal surface a small naked area, increasing in size toward outer end of series, 

 which bears 1 to 3 small, 2-jawed pedicellarise, but slightly larger than the granules. There is con- 

 siderable variation as to the extent of the naked areas, which are much reduced on some specimens. 

 Granulation of inferomarginals similar to that of superomarginals. 



Abactinal surface covered with spaced, low, tabulate plates, arranged with great regularity in a 

 radial series, which is largest, and numerous other parallel series, decreasing rapidly in size toward 

 the margin, where the plates are small and more crowded; in center of disk plates are arranged without 

 oi.ler, and are more or less irregular in a narrow interradial area, winch is free from papulae. Bases of 

 plates of radial areas, when viewed from the inner side, in a prepared specimen an' substellate, regu- 

 larly with six truncate or blunt processes, a shallow sulcus running from the center of the plate to each 

 interradial angle. The plates are entirely free from one another, those of the radial and either 

 adradial series being lengthened transversely, the others rounder. In the vicinity of the marginal 

 plates they become more crowded and lengthened longitudinally. In the center of disk the plates- 

 are roundish, and in the narrow interradial area quadrate, roundish, lozenge-shaped, or. near margin, 

 oliloii<_'. In the proximal portion of the radial anas, small secondary plates or paxillie, with narrow 

 ossicle-like liases, are interspersed rather irregularly, but form a fairly regular series between the radial 

 and either adradial row of plates. The low tabulum surmounting each plate is slightly convex, and 

 bears a central group of robust, flat-topped, quadrate or polygonal granules (about 10 on radial plates) 

 surrounded by a peripheral series of smaller, square-tipped, flattened regular granules. Nearly all the 

 plates bear 1 or - delicate pedicellarise with wide-spatulate jaws, higher than the granules. At the 

 edge of the disk where the plates are very irregular only the marginal series of granules may be present, 

 on account of the compression of the plate. The papulae are conspicuous on account of the open 

 character of the tabulate armature, and are numerous. The abactinal membrane is rather flexible, 

 the plates not being in contact. 



Adambulacral plates nearly quadrate, with a straight furrow margin; armature consisting of a 

 furrow series of s or 7 uutapered, flattened, square-tipped spinelets about half as long as the length of 

 the plate, subequal Or slightly shorter at either end. united at the base by a membrane, very regular 

 and standing parallel; on the actinal surface 2 irregular longitudinal series of smaller grannies, the 

 inner well spaced from the furrow series, as in Mediastcr, and consisting of :i or 4 compressed, square- 



