NO. 5 CLARK : ECHINI OF WARMER EASTERN PACIFIC 295 



per cent of the length but occasionally it is appreciably more, in extreme 

 cases it may be 30 per cent. The general texture of the test is not very 

 stout and hence injuries to the margin are rather frequent resulting in 

 more or less conspicuous deformities. One specimen about 113 mm in 

 length, with the width somewhat less, has the central portion of the 

 petaloid area abruptly raised and flattened, resulting in a curious hat- 

 shaped form as seen from the side. 



Color undergoes very considerable change with the growth. The 

 youngest specimens are pale red violet, almost pink, above and cream 

 color or nearly white below. With increasing size the color deepens. The 

 upper surface becomes a deeper and more purple pink, violet, deep violet, 

 brown violet, brown either j'ellowish or violet tinted, until in old speci- 

 mens the very dark brown of the adult is reached. The ambulacral 

 areas are often of a different shade so that the petals stand out more or 

 less clearly. The cream-colored lower surface of the very young, becomes 

 brownish yellow, yellow brown and ultimately a deep brown. In very old 

 specimens there is a tendency for the ambulacral areas to darken and they 

 may become more or less black at least along the midline. The dark shades 

 of dried adults show considerable diversity, some specimens being quite 

 gray. Young specimens, 25 mm or so in diameter may become deep violet 

 above quite early, but occasionally remain light pink until sometime after 

 that size is reached. 



Distribution. — The original material on which the species was based 

 came from the Gulf of California, Clarion Island, Hood Island in the 

 Galapagos, and Panama. The Velero has extended that range very little, 

 except to the south; the present collection contains a nice set of 12 small 

 specimens, 25-70 mm long, from off La Plata Island, Ecuador, in 45-55 

 fms. In the Galapagos area only once was europacificus met with — a single 

 specimen in Academy Bay, Indefatigable Island in 10-25 fms. It was not 

 found at Clarion or Socorro Islands. From Panama, Costa Rica and 

 Mexico a number of specimens were secured but the bulk of the material, 

 more than 60 specimens, was taken in the Gulf of California, at various 

 points up to Angel de la Guardia Island. The bathymetric range of this 

 Clypeaster seems to be from 10 to 95 fms. 



Tj;/.^.— U.S.N.M. No. 34226. 



Type locality.— Ezy of Panama, 7° 57' N, 78° 55' W, 33 fms. 



Depth.— \0-95 fms. 



Specimens examined. — 102 specimens from 24 stations. 



(Very likely this species is identical with Pfeffer's Alexandria magni- 

 fica. Th. Mortensen) 



