611 



EXPLANATION OF PLATES. 



Plate IY. 



Figure l.—Spicula of Hymenogorgia quercifoiia Edw. ; la. double-spindles; 16, crescent- 

 shaped or scaphoid spicula, — enlarged 1 50 diameters. 



Figure 2.— Spicula of Gm-g'onia gracilis Verrill; 2a, double-spindles; 2h. scaphoid spic- 

 ula, — enlarged 150 diameters. 



Figure 3. — A part of a branch of the same, naiural size. 



Figure 4. — Spicula of Eunicea humilis Edw. ; a, spindles from coenenchj'ma. — enlHrged 

 50 diameters ; &, club-shaped spicula. — enlarged 100 diameters. 



Figure 5. — Spicula of Plexaurella dichotoma K611. ; 5a, a cross-shaped spiculum, with 

 unequcd branches; 5&, a cross witli two of the branches undeveloped, — en- 

 larged 100 diameters. 



Figure <'>. — Cross-shaped spicula of Plexaurella anceps? Koll. ; 6a, one of the larger 

 spindles, — enlarged 100 diameters. 



Figure 7. — Echinasier crassispina A^'errill; part of ray, natural size. 



Figure 8. — Thyone Braziliensis Verrill ; a, oral plates, natural size. 



Figure 9. — Chriodota rotiferum Stimp. ; calcareous wheels of the skin.— enlarged 150 

 diameters. 



Figure 10. — Amphiaster iiisignis Verrill ; ray and part of disk, natural size. 



Plate V. 



All the figures on this plate are from camera-lucida drawings by the author. 



Figure 1. — Renilla amethystina V.; triquetral .siMculum from the disk, — enlarged 100 



diameters. 

 Figure 2. — Stylatula gracilis V. ; one of the spine-like spicula, which support the pin- 



n;e, — enlarged 50 diameters. 

 Figure 3. — Leptogorgia ilorm V. ; a, longer double-spindle; &, stouter double-spindle, — 



enlarged 200 diameters. 

 Figure 4. — L. Agassizii\.\ a. and h. longer double-spindles; c. stouter double-spindle. 



— enlarged 200 diameters. 

 Figure 5. — L. AdamsiiY.; a and b, longer double-spindles; c, stouter double-spindle, 



— enlarged 200 diameters. 

 Figure 6. — L. diffusa Y.; a, longer double-spindle; b, stouter double-spindle, — enlarged 



200 diameters. 

 Figure 7. — L. alba V.; a and b, longer double-spindles; c, stouter double-spindle,— en- 

 larged 200 diameters. 

 Figure 8. — L.pumilaX.] «. longer double-spiridle ; Z*, stouter double-spindle, — enlarged 



200 diameters. 

 Figure 9. — L. rigida V. ; a, longer donble-si>indle ; b and r, stouter double-spindles. — 



enlarged 200 diameters. 

 Figure !0. — L. Californica V.; a, longer double-spindle; ft, stouter double-spindle, — 



enlarged 200 diameters. 



