10 THOMSON AND RITCHIE ON THE ALCYONARIANS. 



The larger spicules are rods with rounded or swollen ends, and have the following 

 dimensions in mm.: 2'5 x 0'25, 2 x 0'2, 2 x 0'15, I'SxO'lS, 1'45 x 0'125, r4xO'l, 

 1'2 x O'l. Besides these there are minute rods, 0'14 x 0'023, O'l x 0'02. 



Locality. 48 06' S., 10 5' W. Bottom at 1742 fathoms, pebbles and diatom ooze. 

 Surface temperature 40 '8 F. 



EXPLANATION OF PLATES. 

 PLATE I. 



Fig. 1. Thouarella brucei, n. sp. A branch with twigs. Nat. size. 



Fig. 2. Primnoisis ramosa, n. sp. A portion of the axis with branches. Nat. size. 



Fig. 3. Primnoella magellanica, Studer. Three whorls of polyps, x 9 



Fig. 4. Gorgonia studeri, 11. sp. The whole fragment, natural size ; and a portion of the axis with 

 verrucas, magnified about 10 times 



Fig. 5. Umbellula durissima, Kdlliker. The largest head, magnified about 2 J times. 



Fig. 6. Paramuricea robusta, n. sp. A small piece of a branch with verrucse, magnified about 2 times. 



Fig. 7. Gorgonia wriyhti, n. sp. Showing the mode of branching. Nat. size. 



Fig. 8. Gorgonia wrighti, n. sp. A portion of the axis, showing the chambers, magnified about 10 times. 



PLATE II. 



Fig. 1. Thouarella brucei, n. sp. 



Fig. 2. Paramuricea robusta, n. sp. 



Fig. 3. Primnoella scotix, n. sp. 



Fig. 4. Gorgonia studeri, n. sp. 



Fig. 5. Amphilaphis regularis, Wright and Studer. 



Fig. 6. Gorgonia wrighti, n. sp. 



Fig. 7. Paramuricea robusta, n. sp. A small portion with two verrucae. x 10. 



Fig. 8. Primnoella scotix, n. sp. The apex with four whorls of polyps, x 8 



Fig. 9. Gorgonia wrighti, n. sp. A small portion of the stem, x 10. 



(HOY. SOC. EDIN. TRANS., VOL. XLI., 860.) 



