330 THE GEOLOGIST. 
geoloofical record," as it seems to indicate the former existence of a family 
or tribe of creatures whose full history must ever remain unknown. 
Order EcMnidm. Genus Echinothuria.* 
E. floris, n. sp. ; test globular?, diameter of compressed specimen 4 
inches, thickness \ an inch, lantern projecting \ an inch ; composed of ten 
segments or double series of imbricating plates, ornamented with obscure 
miliary granules and small spine-bearing tubercles, a few larger than the 
rest; inter amhulacral plates narrow, slightly curved, with the convex 
edge upwards and overlapping ; the alternate plates bearing one large 
extero-lateral tubercle, perforated, and surrounded by a raised ring and 
smooth areola ; largest plates measuring 6 lines in length, the smallest 3 
lines or less (the longest in second specimen equalling 7 lines) ; amhula- 
cral plates 7 lines long, equalling the breadth of the exposed portion of 
eight plates, similar to the former, but curving and imbricating downwards 
towards the dental orifice, and having two small plates, each perforated by 
a pair of pores, intercalated in a notch of the middle of the lower margin ; 
a third pair of pores perforating the plate itself a little external to the 
centre ; primary tubercles few, irregularly distributed. 
Spines of three kinds ; those adhering to the plates minute and striated ; 
fragments of larger spines (not certainly belonging to the species), striated, 
annulated, and furnished with a prominent collar to the articular end (Fig. 
C) ; the third kind minute, clavate and truncate, articulated (?) to a slender 
stalk (Fig. E d). 
Explanation of Plate. 
Fig. A. Mr. Flower's fossil ; a, centre of upper surface ; b, an interanibulacral seg- 
ment ; c, ambuiacram ; d, lateral half of a second iuterarabulacrum. 
Fig. B. Mr. Glass's specimen ; o, dental apparatus ; a, inner surface of apical portion 
of an ambulacrum ; c, e, g, i, I, position of the five amhulacral segments; b, d,f, h, k, 
position of five interambulacral segments, of which only fragments remain ; d, posi- 
tion of small clavate spines. 
Fig. C. Three amhulacral plates near the summit, showing to what extent their outer 
ends are overlapped by the interambulacral plates. 
Fig. D. One of the larger spine-fragments, natural size and magnified. 
Fig. E. Oral disk aud teeth of a recent Cidaris ; a, the five amhulacral segments with 
notched and perforated plates. 
COEEESPONDENCE. 
Foraminifera of the ClialJc. 
SiE, — I was much pleased, in looking over your " Thoughts on Dover 
Cliffs," by meeting with the Foraminifera figured in Plate I. representing 
so many forms ; also with the notes of the figured specimens by Professor 
* Etymologists need not trouble themselves about the derivation of this name; it is 
intended merely to express the dilemma in the writer's mind, arising from imperfect 
knowledge, but which he believes to have no foundation in nature. 
