750 DE. W. B. CAEPEXTEE OX THE STEUCTUEE, PHYSIOLOGY, AXD 



Fig. 9, Central portion of fig. 2 more enlarged, showing the Rosette in situ : — a, a, lines 

 of junction of the First Eadials ; b, b, apertures formed by the coalescence of 

 the spout-like processes of the Eosette with the inner margins of the First 

 Eadials. — ^lagnified 70 diameters. 



Fig. 10. Eosette separated and seen on its dorsal aspect, showing its five flattened trian- 

 gular processes, a, a, and its five intermediate spout-like processes, b, b. — 

 Magnified 100 diameters. 



Fig. 11. Eosette seen from the ventral side, showing around its central orifice irregular 

 projections which coalesce with the processes given-off from the inner margins 

 of the First Eadials ; a, a, triangular processes ; b, b, spout-like processes. — 

 Magnified 100 diameters. 



PLATE XXXIV. 



The following Eeferences are common to both Figures : — 



r\ }•', First Eadials. 



>■", >", Second Eadials. 



1^, >'^ Third or Axillary Eadials. 



hr\ br\ First Brachials. 



br', br\ Second Brachials. 



br\ br". Third Brachials. 



^j,^j, Pinnules. 

 Fig. 1. Horizontal section of Calyx and basal portions of Ai-ms of Antedon rosacetis, 

 flattened out ; showing the axial canals, a, a, of the Eays which communicate 

 by circular branches at b, b (as in Plate XXXIIl. fig. 1), and bifui-cate at c, c, 

 to pass into the Arms. — Magnified 18 diameters. 

 Fig. 2. Interior of the Calyx with basal portions of Arm-s, of a young Antedon, to show 

 the disposition of the Muscles : — m\ m\ five pau-s of muscles passing between 

 the First and Second Eadials ; hi% ??l^ ten pairs of muscles passing between 

 the Third or Axillary Eadials and the First Brachials ; m^, m^, ten pairs of 

 muscles passing between the Second and tlic Third Brachials. — Magnified 30 

 diameters. 



PLATE XXXV. 



Fig. 1. Vertical Section of the Centro-dorsal Piece ; consisting of the Centro-dorsal 

 plate which forms the dome of the cavity, and which is anchylosed at the 

 Imes a, a, a, a to the First Eadials ; b, b, canals leaduig to the articular sockets 

 of the cii-rhi ; c, basal segment of a cii-rhus ; d, d, axial canals of First Eadials ; 

 e, e, portions of Second Eadials; /, Eosette. — Magnified 70 diameters. 



Fig. 2. Longitudinal Section of three of the basal segments of a Dorsal Cirrhus, showing 

 the central articular processes, and the ligaments interposed between their 

 peripheral surfaces. — Magnified 70 diameters. 



