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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 81 



Additional material examined. — On April 15, 1929, E. F. Ricketts 

 dredged this species in shallow water in Monterey Bay. I collected 

 a third specimen on Monterey Peninsula, intertidal, in the summer of 

 1930 ; all three are very similar to one another. 



Desei^ption. — Shape, massive. Size, 4 cm thick, 10 cm in diameter. 

 Consistency, mediocre; the ectosome is tough and leathery. Color 

 in life and when preserved, drab, except that in life the ectosome 

 in places is very dark brown, paling after death. Oscules, oval, size 

 about 1 by 2.5 mm ; there is one for about every 5 square centimeters. 



FiGUKB 15. — Penares cortius de Laubenfels : A-0, X80; others, X 1,333. A-A, 

 range in size of the peculiar microsclere, to the same scale as the megascleres; 

 H, unusual shape of the same spicules, with the centrotylote modification ; B, G, 

 dichotriaenes ; D, E, unusual shape and size for the principal spicules ; F, O, 

 oxeas ; I-K, oxyspherasters 



They are often on low prominences about 3 mm high and 10 mm 

 in diameter. Pores, at least 65/i, in diameter ; spaced about 250/i, from 

 center to center. Surface, superficially smooth to minutely 

 punctiform. 



Ectosomal structure, a densely felted mass of the bicurvates, con- 

 taining also the cladomes of the dichotriaenes ; thickness about 200^. 

 This is very easily detachable. Endosomal structure " crumb-of- 

 bread," with evident spicules (diactines) mostly in confusion, but 

 with traces of tracts. Principal, or ascending, tracts, 170/a to 230/t 

 in diameter, fascicular, few and scattered. 



