EXPLANATIOX OF THE PLATES. 133 



Fig. 4. Same as Yi<r. 2, seen from the al)actinal side, to show the network of the abactinal surface and 



the projectin;f knobs forming tlie support of the eliisters of spines of that surface. 

 Fig. 5, Longitudinal section througli the median line, seen in profile. 



All figures natural size. 



The colorin;; of this species is of all shiules, between a brilliant red and a lij;ht orange or a dark violet. 



PLATE XIII. 

 Pycnopodia helianthoidbs. 



Fig. 1. Portion of disk, seen from abactinal side, with papilla; fully expanded (from life). 



Fig. 2. Same as Fig. 1, seen from the actinal side. 



Fig. 3. Actinal view of central part of the disk, showing the connection of the arms around the central 



opening. 

 Fig. 4. Limestone network of part of the abactinal membrane, with the pillar separating adjoinin"^ arms 



seen from the interior. 

 Fig. 5. Profile view of the extremity of one arm. 

 Fig. 6. Interior view of the arm ; the abactinal membrane is removed, showing the mode of connection of 



adjoining arms at actinostome, ambulacral vesicles all removed. 

 Fig. 7. Same as Fig. G ; seen from below, the soft i)arts all being removed. 

 Fig. 8. Profile view of Fig. 6. 

 Fig. 9. Section across Fig. 6. 



Fig. 10, 10". Profile views of two of the large spines of the abactinal surface. 

 Fig. 10', 10'". Tlie same spines, 10, 10", seen from above. 



Figs. 1-5 are natural size ; all others slightly enlarged. 



The color of the abactinal surface varies greatly in this species, from a brilliant carmine to yellow, violet, or bright 

 vermilion, with the intermediate shades of orange. 



PLATE XIV. 



LiNCKIA GUILDINGII. 

 Fig. 1. Seen from above. 

 Fig. 1'. Enlarged tip of one of the arms. 

 Fig. 2. Fig. 1, seen from the actinal side. 

 Fig. 2'. Magnified portion of arm of Fig. 2. 



Fig. 3. Preparation of actinal side, showing the limestone plates after the granulation is removed. 

 Fig. 3'. Magnified view of opening of actinostome of Fig. 2. 



Fig. 4. Preparation of abactinal surfiice, showing the limestone plates of that surface. 

 Fig. 4'. Enlarged view of madreporic body. 

 Fig. 5. Interior view of abactinal surface of one of the arms, showing the small openings lefl between the 



nearly united plates. • 



Fig. 6. Section across one of the arms, to show the depth of the ambulacral furow, with its single line of 



ambulacral pores. 



Linckia is generally of an ashy-violet color, with darker spots scattered over the abactinal surface of the arms. 



ASTERINA FOLIUM LUtL 



Fig. 7. Actinal view prepared to show the plates of that surface. 



Fig. T. Enlarged view of plates, forming edge of actinal opening, in Fig. 7. 



Fig. 8. Somewhat enlarged view, natural attitude, with suckers expanded. 



Fig. 8'. Enlarged view of arm, pillowing ocular tentacle, at base of pointed terminal ambulacral tube. 



Fig. JD. Water-tubes of abactinal siu-faee somewhat enlarged. 



Figs. 1-7, natural size ; others somewhat enlarged. 



The abactinal surface of Asterina is of a pea-green color. The actinal surface is more yellowish. Specimens frequently 

 occur of a yellow color on both sides. 



