470 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



described in more detail is an unidentifiable genus (see yp. 455, 456 of 

 this paper). 



DIPLOASTREA HELIOPORA (Lamarck) Matthai. 



Plate 134, figs. 1, la, 16, lc. 



1816. Astrea heliopora Lamarck, Hist. nat. Anim. sans Vert., vol. 2, p. 265. 

 1914. Diploastrea heliopora Matthai, Linn. Soc. London Trans., ser. 2, Zool., 



vol. 17, p. 72, pi. 20, figs. 7, 8; pi. 34, fig. 9. 

 1917. Diploastrea heliopora Vaughan, Carnegie Inst. Washington Pub. 213, 



p. 143, pi. 59, figs. 5, 5a. 



Figures 1, la, lb, lc, plate 134, are intended to illustrate the generic 

 characters of the genotype. Plate 134, figure 1, is a natural size view 

 of the calices; figure lb is a view of the calices enlarged four times. 

 These figures illustrate the imperfect, synapticulate wall as seen from 

 above, the dentate septal margins, and the trabecular columella, It 

 should be noted here that the septal margins are not so prominent nor 

 are they so coarsely dentate in all specimens. Plate 134, figure la, 

 illustrates the costae of the edge of the lower part of the corallum, 

 four times enlarged, and shows that the common wall originally is syn- 

 apticulate and perforate. Plate 134, figure lc, is a longitudinal section 

 of the corallites, four times natural size, to illustrate the interrupted 

 corallited walls, the perforate character of the septa, and the synap- 

 ticulae and dissepiments on the septal faces. 



Geographic distribution. — Diploastrea heliopora is found on the 

 living coral reefs of the Indo-Pacific from the east coast of Africa, 

 French Somaliland, eastward at least as far as the Fiji Islands. The 

 specimen here figured is from Djibouti, French Somaliland, collected 

 by Dr. Charles Gravier. 



DIPLOASTREA CRASSOLAMELLATA (Duncan) Vaugha,n. 



Plate 135, figs. 1, 2, 3, 4, 4a, 5, 5a, 56; plate 136, figs. 1, la, 16: plate 137. figs. 1, 2, 3, 



4, 4a, 5. 

 1863. Astraea erassolamellata Duncan, Geol. Soc. London Quart. Journ., vol. 19, 



pp. 412-117, pi. 13, figs. 1-7. 

 1866. Heliastraea erassolamellata Duchassaing and Michelotti, Sup. Corall. 



Antilles, p. 86 (of reprint). 

 1857. Heliastraea erassolamellata Duncan, Geol. Soc. London Quart. Journ., 



vol. 24, p. 24. 

 1870. Heliastraea erassolamellata Duchassaing, Rev. Zooph. Antilles, p. 30. 

 1902. Orbieella erassolamellata and Brachyphyllia sp. Vaughan, Geol. Soc. London 



Quart. Journ.. vol. 57, p. 497. 



The following are Duncan's original descriptions of the general 

 characters of this species and of the typical form, and his synopsis of 

 the seven varieties into which he subdivided it: 



General description. — "A group of forms from the Marl presents 

 the following structural characteristics: Corallum very massive and 

 large, with an irregular upper surface, which is convex in some parts, 



