hill: geology of Jamaica. 249 



little more than a millimeter apart, but the average is as first stated. The 

 calices on the upper side are not at all elevated above the coenenchyma,. but on 

 the lower side they stand about 1 mm. above it. The outside of the projecting 

 part of the corallite has distinct equal costse corresponding to each septum. I 

 observed no perforations between the costse. The cccnenchymal surface is 

 densely and minutely granulate; when the outer surface is worn away its 

 porous nature is revealed. Septa : there are six septa larger and more prominent 

 than the others ; in each well preserved calice examined, between each pair of 

 larger septa is a pair of smaller septa. The septa are stout, so far as could be 

 made out solid, imperforate, and have entire margins. There is no columella. 



Locality. Near Cambridge Station, south of Montpelier, St. James Parish, 

 Jamaica (R. T. Hill, collector). 



Types. Museum of Comparative Zoology, Harvard University. 



Remarks. This species has considerable resemblance to Bendracis haidingeri, 

 Reuss, from Oberburg, Steiermark,i ^Iso found at Castel Gomberto, Monte 

 Grumi and Monte Viale, Italy. Felix ^ reports it from Gebel Auwebet, Egypt. 

 The following notes made on specimens in the Vienna Hofmuseum show the 

 differences. The calices of I), haidingeri tend to be constricted above. There 

 are two complete cycles of septa, with members of the third cycle sometimes 

 present. On the lower side of the projecting part of a corallite there are two or 

 more costse for each septum. 



PORITES, Lamarck. ' 



Porites reussiana, Duncan. 



1865. Porites reussiana, Duncan, Quart. Jour. Geol. Soc. London, Vol. XXL p. 8 

 (original description), PI. I. Fig. 2. Another reference, p. 7. 



1868. Porites reussiana, Duncan, Quart. Jour. Geol. Soc. London, Vol. XXIV. 

 p. 25. 



Original Description, " The corallum is in more or less cylindrical branches, 

 which leave the stem at an acute angle, and are often flattened, and always 

 rugged and gibbous. The calices are large, irregular in size, and shallow. The 

 columella is small, and there are sometimes more than six distinct pali. The 

 septa are from eight to twenty-four in number. Diameter of calices often 

 ■^Q inch ; that of the branches from -^^ to \^ inch. 



" Locality. Upper Clarendon District, Jamaica." 



I saw the type in the collection of the Geological Society of London, and add 

 a few notes to the above description. The usual number of cycles of septa is 



1 Denksclirift d. Wiener Akad. d. Wissenschaft. (Mat. Natur.), Bd. XXIIL 1st 

 Abtheil, 18G3, p. 27, PI. VIII. Figs. 2-5. 



2 Felix, Zeitschrift d. deutsch. geolog. Gesellschaft, 1884, Bd. XXXVI. p. 424, 

 PI. III. Fig. 12. 



