1915.] NATURAL SCIENCES OF PHILADELPHIA. 89 



reducta Koehler (referred to Bathypectinura by Dr. H. L. Clark) .^ 

 It is, however, distinguished from 0. Ijungmani by the presence of 

 primary disk plates, by coarser disk scales, by shape of radial shields, 

 by the disk margin being not so closely granulated, and by the shape 

 of the oral shields; from 0. custos by the presence of primary disk 

 plates, by coarser disk scales, by the shape of the radial shields, by 

 the adoral shields not meeting each other within, by the shape of 

 the first and second ventral arm plates, by the presenc3 of lamellar 

 plates at the arm bases, and by shape of dorsal arm plates; and 

 from 0. reducta by dorsal side of disk being free of granules, by 

 radial shields not being divergent, and by shape of ventral arm plates. 

 Disk covered with fine, imbricating scales, among which the six 

 primaries are more or less distinct; the radial plates are smaller and 

 less conspicuous than the central plate. Radial shields triangular, 

 with acute inner angles, twice as long as wide; those of a pair are 

 nearly parallel, being separated from each other. Ventral inter- 

 brachial areas are closely covered with very fine granules. Oral 

 shields large, triangular, with strongly curved outer border, less 

 curved lateral sides, obtuse inner angle and perfectly rounded lateral 

 angles. Adoral shields large, triangular, long, tapered within to an 

 acute point, but they do not meet. Lamellar plates and fine granules 

 occur on dorsal and lateral surface of free arm bases. Dorsal arm 

 plates triangular at first, but soon becoming quadrangular with 

 rounded outer corners and curved lateral borders", much wider 

 without than within. First ventral arm plate is small, triangular, 

 with rounded -angles, nearly as wide as long; those beyond are 

 pentagonal, with an inwardly directed angle, which is covered by 

 the preceding plate; outer border curved, and lateral borders con- 

 cave and bounded by tentacle pores. A single large, oval tentacle 

 scale occurs on the abradial side of each pore; besides, on the adradial 

 side of a few basal pores, there are present one or two rudimentary 

 tentacle scales, more or less covered over by the abradial one. 



The type is 4.5 mm. across the disk, 35 mm. in arm length and 0.8 

 mm. in arm width at base. Color in alcohol: yellowish gray above 

 and white below; arms banded with dark gray. 



One specimen; off Kotsujima, Sagami Sea. 



It is recorded that the above specimen was taken with a coral -net, 



' Ophiopeza reducta appears to me to be referable to Ophioplax. The presence 

 of only three long, cylindrical arm spines and of only five oral papillae, the annu- 

 lation on the arms and the naked oral plates are all characters of Ophioplax, 

 but not of genuine Bathypectinura. 



