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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 81 



First microscleres, oxyspheraster (fig. 12, Z, L, M)', diameter 21/2M 

 to 12ix. Second microsclere, tylospheraster (fig. 12, /, /) ; diameter, 

 lO/u. to llfi. These are rather uncommon. 



Remarks. — This species is peculiar for the very large average size 

 of its megascleres; not many other Stellettas have quite such enor- 

 mous ones. S. clarella from central California has a few as large 

 and, like S. estrella., has very inconspicuous vents, but the two are 

 separated in many ways. The northern form has chiefly strongylote 

 rayed asters; the southern form has few or none of that sort, but 



Figure 12. — Stelletta cstrella de Laubenfels : Spicules A to H, X80; 

 others, X 1,333. A-E, endosomal spicules ; F, O, and //, variation 

 in ends of the axeas and esactinal ends of the tetractinal mega- 

 scleres ; /, J, tylospherasters ; K-M, oxyspherasters 



instead has two distinct sorts, one with decidedly oxeote and the 

 other with tylote rays. Two other features separate estrella not 

 only from clarella but indeed from most other Stellettas; first, the 

 peculiarly short clads typical of this species, and second, the lack 

 of anatriaenes. That the clads of the plagiotriaenes project beyond 

 the surface is also noteworthy. 



Family THENEIDAE Sollas 

 Genus L'OECILLASTRA Sollas 



POECILLASTRA RICKETTSI > de Laubenfels 



PoeciVastra rickettsi de Laubenfexs, 1930, p. 26. 



Holotype.—JJ.S.^M. No. 21482 ; B.M. No. 29.8.22.7. 

 Type locality. — Monterey Bay, Calif., 800 meters; collected by 

 E. F. Ricketts, Jul}^ 192.5. Notes on other specimens that he col- 



1 Named for B. F. Ricketts, of the Pacific Biological Laboratories, Pacific Grove, Calif. 



