﻿186 ASTROPHYTON AGASSIZII. 



Astrophyton Agassizii Stimpson. 



" The Basket Fish." Philosophical Transactions, IV. p. 1152. 1670. (J. Winthrop.) 

 Astrophyton scutatum ; scuto ro'a'o ? Linck. De Stel. Mar., p. C5, PI. XXIX. & XXX. 1733. 

 Euryale scutatum Gould (non De Blainville). Invertebrata of Mass., p. 345. 

 Astrophyton Agassizii Stijipsox. luverteb. Grand Manan, Sniithsou. Coutrib., VI. p. 12. 1854. 



Sjyecial Marks. — Radial ribs yellowish ; interbrachial spaces brown- 

 ish. Numerous short, conical spines irregularly disposed on the radial 

 ribs. Interbrachial spaces above naked, or -with very few blunt, short 

 spines. 



Descri2)tion of a Specimen. — Diameter of disk, 73""°- ; outer side of 

 madreporic shield to outer corner of opposite mouth-slit, 24°"°' ; width 

 of arm at base, 24°""- ; length of arm, measured along the branches to 

 the tip of the longest branch, 260""°-. The distances from one fork to 

 the one beyond it along the longest branch, were as follows (two 

 branches from different arms are compared) : — 



to second, . . . 20™"'- . . . 15™™- 



third, .... 29 •' ... 32 " 



fourth, ... 41 '• ... 40 " 



fifth 28 '= . . . 37 " 



" sixth, . . . . 40 '• . . . 25 ■' 



" seventh. . . . 19 '• . . . 34 " 



eighth, . . . 18 ■' . . . 18 '■ 



nhith, ... 13 •' ... 19 " 



tenth, ... 11 - ... 13 " 



eleventh, . . 9 "... 11 " 



twelfth, ... 7 " . . . 9 " 



end, .... 9 '• . . . 7 •' 



Distance from outer side of madreporic shield to inner points of mouth- 

 papillaj, to that between outer corners of mouth-slits, 15 : 8. Mouth- 

 papillae, tooth-papilltB, and teeth, about twenty-four in all, cylindrical, 

 tapering, thorn-like ; mouth-papillce forming a row of about ten, of 

 which those near corners of mouth-slits are smallest ; length of tooth- 

 papillae about 1.8°°'-. Madreporic shield broad heart-shape, with the 

 point outward ; irregular, indistinct ; length to breadth, 4.2 : 6.2. 

 Under surface of arms smooth and polished, with faint cross lines 

 between the joints. Top and sides of arms nearly naked as far as the 

 second fork of the arm, but beyond that granulated. Grains smooth, 

 rounded ; above, crowded ; on the sides more scattered ; as they ap- 

 proach the end of the arm they become more confined to vertical 

 ridges, and more regular in arrangement ; and at the tip of the arm 



