430 On new Genera and Specks o/Biisingidne. 



FreyelUdea microplax, sp. n. 



Diagnosis. — Rays 12, not deciduous, only moderately lons^, 

 with a short, swollen genital region about 4 r in length. 

 Disk closely covered with short spinelets, 4 or 5 to a plate ; 

 cpiiital region of ray covered with small, transversely oriented, 

 elliptical, somewhat irretrular plates bearing groups of 2 to 8 

 small spiiielets ; 19 or 20 j)latcs can be counted across ray 

 at widest part. Short lateral spine opposite alternate 

 adambulacral plates. Adambulacral armature: laboral furrow 

 spinelet, and 1 subambulacral spine, with truncate enlarged 

 lip at base of ray ; first adambulacral plates of adjacent rays 

 not fused, the outer end of the mouth-plates intervening; 

 oral armature : 3 actinostomial spinelets and 1 short, sharj), 

 suboral spine. E.= 170^-mm., ?' = 10 mm., R=17-t-r; 

 thickness of disk 4 mm.; width of ray at base 4*5 mm.; 

 breadth of actinostome 13 mm. 



Type-localiti/. — 'Albatross' station 3342, off British 

 Columbia (52° 39' 30" K, 132° 38' W.), 1588 fathoms, grey 

 ooze and coaise sand, bottom temperature 35°'3 Fahrenheit. 



ASTROCLES, gen. nov. 



Diagnosis. — As given in foregoing synopsis. • 



Tills curious genus agrees with FreyelliJea in its most 

 important features — the absence of a proximal adambulacral 

 syzygy, absence of marginal plates above the first few 

 adambulacral plates, and the presence of only two gonads 

 to each rav. The differential characters are given in the 

 synopsis. The following species is the type of the genus. 



Aslrodes actinodetus, sp. n. 



Diagnosis. — Rays 11, not very deciduous ; disk fairly 

 large, covered with circular plates bearing 1 to 3 spinelets ; 

 genital region of ray 3'5 to 4 r in length, or about one-sixth 

 total length of ray, and crossed by 25 to 27 pretty regular 

 transverse arches of depressed, elliptical, crenulate plates 

 covered with a felling of minute pedicellarife and bearing 

 small spinelets in transverse series ; intervals between arches 

 without plates or pedicellarife ; lateral spine opposite alternate 

 ailambulacrals, very slender and delicate ; adambulacral 

 armature consisting of 1 aboral furrow spinelet with tip 

 greatly broadened and subtriangular in form, and 1 sub- 

 ambulacral spine, those on proximal half or two-thirds of 

 genital region with an enlarged bifid tip; mouth-plates with 

 3 actinostomial spines, expanded, flattened, and more or less 



