TRIBE I. ASTR^ACEA. 311 



GENUS IV. HALOMITRA. DANA. 



FungidcB liberce, gemmatce, explanatce, polypis omnino sparsis, (utrisque 

 longe tentaculatis ?). Coralla convexa ; oririmis grandibus, undique 

 sparsis; lamettis brevibus (semipollice non minoribus},crassimis,crasse 

 dentatis, radiatis;, super fide inferiori echinatd. 



Free Fungidse, budding and explanate; polyps throughout scattered 

 (each with a separate circle of large tentacles ?). Coralla convex, 

 oririmes large, every where scattered; lamellae short and stout (not 

 less than half an inch), coarsely dentate, radiate ; under surface 

 echinate. 



The coralla of the Halomitrse, though like those of the Polyphyllise 

 in not having a medial compound oririme, are peculiar in their coarse 

 and coarsely dentate radiated lamellae. The only species known is 

 conically cap-shape, and very stout and heavy. The polyps, as may 

 be inferred from the corallum, appear to have each a distinct circle of 

 tentacles, like those of the Herpetolithi, and these are probably of 

 large size. This genus is made for the Mitra Polonica of Rumphius, 

 the Fungia Pileus of Lamarck, as the coral has not the characters 

 of either of the other generic groups. The name is from a xs, sea, 

 and jus-pa, mitre. 



HALOMITRA PILEUS. (Lamarck.) Dana. 



H. maxima, hemispherico-conica. Corallum -l" crassum, lam,ellis 

 crassis, valde inciso-dentatis, scepius J $" longis (ad peripheriam fere 

 1^"); subtus, crasse et confertissime radiatim echinatd. 



Very large, hemispherico-conical. Corallum to l^ inches thick, 

 lamella? stout, strongly inciso-dentate, usually to ^ of an inch 

 long (nearly 1J at the margin); under surface stoutly and very 

 crowded ly radiately echinate. 



Plate 21, fig. 2, cross section; 2 a, outline of lamella ; 2 b, another 

 variety. 



East Indies and Pacific. The Feejees. Exp. Exp. 



