152 MAftKKrOKAKTA. 



Specimen No. 28. Obviously much abrased, calicles smaller than in No. 27, 4 mm., 

 septa somewhat thicker, wall-reticulum closer and thicker. This is one of Lonsdale's original 

 specimens figured in Dixon's ' Sussex,' 1850, pi. i. fig. 5, p. 139. Geol. Dept. 48333. 



Specimen No. 29. PI. X 6 . fig. 5. Like No. 28 ; calicles still smaller, 3 mm., and walls 

 somewhat denser. Geol. Dept. 48334. 



Specimen No. 30. PI. X*. fig. 7. A fragment, and one of the most beautiful of all the 

 specimens. It is doubtful whether the original surface has been abrased. Calicles large, 

 5 mm., fairly uniform. Septa delicate, but very frosted, and not more than 1 mm. long 

 before they unite with an immense columellar tangle, which is a delicate reticulum of smooth 

 flakes. The walls are of close flaky reticulum, as if finely worm-eaten. The vertical sections 

 show the outer portions of the septa largely laminate, while the inner portions, which help to 

 form the columella, are very perforate. Bowerbank's original figure was apparently intended 

 to represent a specimen with walls and septa like these, but without a columellar tangle. 



Geol. Dept. 48335. 



Specimens Nos. 31 and 32. Two specimens, piled up almost into columns above their 

 pebble bases. The wall-thread tends to thicken, and the septa to be wavy and irregular. 



Geol. Dept. 1854. 



142. Goniopora Hampshire (i)l. 

 [Brockenhurst, Hampshire (Oligocene, Headon Beds) ; British Museum.] 



Litharxa brockenhursti, Duncan, British Fossil Corals, Mon. Pal. Soc, Suppl. Part i. (1866) p.' 49, 

 pi. vii. figs. 16 and 17. 



Description. — Form of stock unknown ; massive 



Calicles very unequal in size, the largest under 4 mm. ; the walls are thin and seem to be 

 composed of a stout gyrating thread of very irregular thickness, sometimes forming single 

 meshes. 



The septa very much thinner than the wall-thread, in three cycles arranged in the typical 

 way, but the formula is obscured by the large columellar tangle. The primaries are perhaps a 

 little more conspicuous than the rest. The septa are very irregularly and slightly echinulate, 

 but very highly perforate, the pores being large and round and separated by thin nearly 

 vertical and horizontal threads. The large columellar tangle is of flaky reticulum, and in the 

 larger calicles (3 • 5 mm.) it may be 1 • 5 mm. across, in the smaller calicles it is not so con- 

 spicuous. The skeleton is exquisitely delicate and friable. 



The single type specimen, figured by Martin Duncan, is only an irregular fragment, and, 

 unfortunately, gives no clue to the original shape, nor to the characters of the calicles of the 

 original surface. Duncan's figure and description give some of the appearances, but he did 

 not discover that there are larger and more regular calicles with conspicuous columellar 

 tangles, and altogether very unlike the small thin-walled nearly rectangular calicles which 

 he figured. 



