492 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



The corallum is usually more or less turbinate in shape^ rising from 

 a narrow base, expanding upward, with, a lobulate, 'but somewhat 

 flattish upper surface. The dimensions of the largest specimen are as 

 follows: Least diameter of fracture on basal surface, 5 cm. ; height 18.5 

 cm. ; diameter of upper surface 22 by 25.5 cm. Some .specimens are 

 more or less columniform; others are glomerate. 



The calices are from 2 to 2.5 mm. in diameter and are separated 

 by distinct, straight walls, or there is some costate intercorallite 

 reticulum. 



The septal formula is normal for Gonioporaj but the septa are more 

 distinctly lamellate than is usual. There is a wide, detached, septal 

 granule, that is usually compressed in the septal plane and is plate- 

 like. Pali well developed; plate-like in many calices. 



This species will be described in detail and figured in a forthcoming 

 report. 



Localities and geologic occurrence. — ^Antigua, at nearly every expo- 

 sure of the coral reef in the Antigua formation, collected by T. W. 

 Vaughan. 



Porto Rico, zone C, near Lares, collected by Bela Hubbard, of the 

 New York Academy Porto Rico investigations. 



Arube, Serro Colorado. 



GONIOPOEA REGULARIS var. MICROSCOPICA (Duncan). 



1863. Alveopora microscopica Duncan, Geol. Soc. London Quart. Journ., vol. 19, 



p. 426, pi. 14, fig. 5. 

 1867. Alveopora microscopica Duncan, Geol. Soc. London Quart. Journ., vol. 24, 



p. 25. 



Duncan based Alveopora microscopica on a silicified specimen (No. 

 12951, Coll. Geol. Soc. London), of which I have a photograph. 

 This is a small calicled species of Goniopora, with rather strikingly 

 lamellate septa. I obtained in Antigua three specimens that I 

 identify with Duncan's species, which probably is only a variant of 

 Goniopora regularis. G. microscopica has a more regularly rounded 

 corraUum and smaller calices, 1.25 to 1.5 mm. in diameter; other- 

 wise I detect no important differences. 



Locality and geologic occurrence. — Antigua, stations 6856, Friar's 

 Hill, and 6881, Willoughby Bay, Antigua formation, collected by 

 T. W. Vaughan. 



GONIOPORA JAGOBIANA, new species. 



Plate 144, figs. 1, la, 2, 2a, 8, 3a. 



A description of the type (pi. 144, figs. 1, la), is as follows: Coral- 

 lum obtuse, columniform. Horizontal diameter 160 by 165 mm.; 

 height 133 mm, +, top damaged, when perfect probably about 210 

 mm. tall. Successive shells of skeletal substance are recognizable. 



Calices shallow, polygonal in outline, usual diameter slightly more 

 than 3.5 mm. Intercorallite walls rather narrow, with some reticu- 

 lum, septa traceable through it, in places about 1 mm. wide. 



