600 METALIA PECTORAL1S. 



Samoa; Sandwich Islands; Australia; Mauritius; Panama. 



Metalia pectoralis 



Echinus grandis G.MF.L., 1788, LlNN. Syst. Xat. 

 ! Metalia pectoralis A. A.G., 1 S72. Rev. Ech., l't. I. p. 144. 

 < - Pari II. p. 3G1.) 



/'/. XXI. f. 4, 5. 



Wcsl In lia Islands ; Florida. 



Metalia sternalis 



! Spalangus sternalis Lamk., 1816, An. -. Vert., |>. 31. 

 ! Metalia sternalis Gray, 1855, Cat. Etec. Ech., p. 51. 



/'/. XXI. f. ;. .-,; Pi. XXI'.f.s 9; PL XXXII.f. //. / .<; PL XXXVIIf. 20. 



This species -row- to a large size, and the differences due to age are quite 

 remarkable. In the largest specimens 1 have seen, measuring l."iO"""- in 

 length, the outline of the test from above is elliptical, slightly angular. 

 truncated posteriorly ; the anterior edge deeply indented at the ambitus 

 by the ambulacral groove. Seen in profile, the test rises vertically at the 

 anterior extremity almost to the summit. The apical system is anterior, 

 within the depressed abactinal part of the interambulacra, which rise above 

 the general level of the termination of the petals; the posterior pari of the 

 tesl is concave; from the apical system towards the posterior edge the abac- 

 tinal surface of the test is flattened. In specimens slightly younger the pos- 

 terior part of the test, seen in profile, is straight ; it is even convex near the 

 edge of the posterior pari of the interambulacrum. The genital pores are 

 large, circular, close together. The odd ambulacral groove is shallow, flat at 

 the ahactinal pole, becoming deeper towards the edge, but narrowing again 

 below the peripetalous fasciole. The lateral anterior ambulacra are sunken. 

 broad, elongate, somewhat rounded at the outer extremity ; the poriferous zones 

 broad ; the pores large, connected by a deep groove. The ahactinal part of 

 the anterior ambulacra is pointed ; the poriferous zones forming a slight angle 

 with the trend of the rest of the petal. The lateral posterior ambulacral 

 petals, for a considerable distance from the apical system, are narrow, elon- 



