DITREMATA. G7 



Goniaster (Agass.). Body thick, bordered by a 

 series of plates edged with spines ; avenues bor- 

 dered by transverse rows of spines. 



G. Templetoni. Fig. 102 ; \. G. equestris. 



Abbensis. 



Sub-Family IV. Asteriana. 



Asterias (Linn.). Body star-shaped; rays flat, 

 with a border of marginal plates ; avenues bor- 

 dered by three sets of spines. 



A. aurantiaca. Fig. 103 ; -5-. 



103 104 



Luidia (Forbes). Body star-shaped, rnany-rayed; 

 rays flat, covered above with spine-bearing warts ; 

 avenues bordered by two sets of spines. 



L. fragilissima. Fig. 104 ; -^j. 



Sub-Class II. Diteemata. 



Shell calcareous, forming a spherical or 

 disk-like shield, composed of immoveable 

 plates ; locomotion by suckers and spines. Echinoidea. 



No shell; but the leathery skin con- 

 taining calcareous reticulated pieces : gul- 

 let surrounded by a calcareous ring; 

 body cylindrical; locomotion usually by 

 suckers ; mouth encircled by feathery 

 tentacles Holothuroidea. 



