40 HAWAIIAN AND OTHER PACIFIC ECHINI. 



Station 4S94. Southwest of Goto Islands, Japan. Bott. temp. ? 95 fnis. 

 Ciy. s., brk. sh., p. 



Station 4895. Southwest of Goto Islands, Japan. Bott. temp.? 95 fms. 

 Gy. s., brk. sh., p. 



Station 4937. Kagoshima (Julf, Japan. Bott. temp. 64.8°. 58 fms. M., 

 lava, p. 



Station 4948. Between Kagoshima and Kobe, Japan. Bott. temp. 62.6°. 

 65 fms. Dk. gy. vol. s., brk. sh., p. 



Station 5071. In Suruga C>ulf, Japan. Bott. temp. 708°. 87 fms. Char, 

 of bott.? 



Station 5095. Gulf of Tokyo, Japan. Bott. temp. 57.8°. 58 fms. Fne. 

 bl. s., br. sh. 



Bathymetrical range, 53-106 fms. Extremes of temperature 70.8°-55.9°. 



P'ourteen specimens. 



Clypeaster leptostracon.' 



A. Agassiz and Clark, 1907. Bull. M. C. Z., 50, p. 24S. 



Plates 122, figs. S, 9; 123, figs. 17-20; 135, figs. 3-5. 



Length 38 mm.; breadth, 31 mm.; height, 7.5 mm.; mouth sunken but 

 very little below the sides of the test. Test quite flat distal to petals, the margin 

 a trifle thicker than the test a little ways in from the margin; petaloid area 

 abruptly elevated; orally the test is flat, the region about the mouth shghtly 

 concave. Tuberculation of test sparse; primary tubercles relatively large with 

 sunken areolae, less than UK) to a square centimeter of test surface, aborally; 

 ridges between poi'e-]3aii's of unpaired petal with no primaries or occasionally a 

 single one; miliar}- tubercles fairly numerous, not crowded and rather evenly 

 distributed. Madreporite pentagonal, 2 mm. across, the ocular plates and 

 pores fairly distinct; genital pores present only in interambulacra 2 and 4, 

 close to madreporite. Unpaired petal with 24 pore-pairs on each side, 9 mm. 

 long, 5.5 mm. wide near tip, open by more than 3 mm. ; median area 3-3.5 mm. 

 wide; poriferous areas thus 1 mm. wide each. Anterior petals 7.5 mm. long, 

 open by only 1 mm., their greatest width, 4.75 nun., a little further from tip 

 than in unpaired petal. Posterior petals 8.5 mm. long, 5 mm. Avide, open by 

 about 2 mm., their form much like that of unpaired petal. Periproct 2 mm. from 

 margin, about 2 nun. across, covered with miliary bearing plates. 



' XiwTos = delicate + osTpamv = shell, in allusion to the thinness of the test-wall. 



