COLANGIA. 31 



ASTRANGIA M.-Edw. & H. 

 Astrangia solitaria Verrill. 



Asti-angia solitaria Vkrrill. Bull. Mus. Conip. Zool., No. 3. 



CaryoplnjUia solitaria Lesueur. Jour. Phil. Avad. Nat. S(;., I., p. 180, PI. VIII., fig. 11, 1817 ; and 



Mem. (lu Mus., T. VI., p. 273, Plate XV., fig. 1. 

 Astrangia phyllangioides f DuCH. & Mich. 



Dead specimens off Double-Heacled Shot Key, in 315 fathoms. 

 The same remarks apply to this species as to Phijllangia americana. 

 Both are rather common shoal-water species. 



COLANGIA PouRT. 



Corallum immersed in an expanded epithecal membrane, forming 

 several successive stories, following the growth of the coral. Pri- 

 mary and secondary septa entire ; those of the lower cycles dentic- 

 ulate. Well-developed pali in front of the tertiaries. Columella 

 lamellar or papillose, not much developed. The genus is chiefly dis- 

 tinguished by the highly developed epitheca from Phyllangia, which 

 has, none, or only a false one formed by a coralline growth. 



Colangia immersa Pourt. 



Corallum incrusting, in loose clusters, the corallites tending to 

 develop in rows, immersed in an epithecal membrane, stretching 

 out horizontally from the margin of the calicles, and forming anew 

 when the corallites increase in height. No costee visible. Calicles 

 round or somewhat elongated ; fossa shallow. Septa thin, smooth, 

 with very few granules, in six systems, generally complete. Four 

 cycles. Primaries exsert, with straight perpendicular inner edge. 

 Secondaries not exsert, having, like the primaries, an entire edge. 

 Tertiaries with rounded denticulations. Pali prominent, thin, 

 rounded, in front of tertiary septa. Columella in shape of an 

 irregular lamella with a few lateral papilla3, or sometimes simply 

 papillary. 



Diameter of calicles, 7 mm. 



Like the other Astrangiacese, this is a shallow-water form, found on 



