Chap. IX.] LOWER SILURIAN ECHINODERMS. 
191 
tites. Echinosphserites aurantium, the commonest species in the north of Europe, 
is rare in Britain ; but E. Balticus, Foss. 33. f. 1, and E. (Caryocystites) granatus, 
f. 5, both of them frequent in the Lower Silurian of Scandinavia, are found 
profusely in my old fossil-bearing locality of Sholeshook in Pembrokeshire; 
and thus our British Silurians are well paralleled and co-related with their 
foreign analogues. EchinosphEerites arachnoideus, Forbes, occurs with them, 
and Sphaeronites Litchi, Forbes, a globular species having pores arranged in pairs, 
and five protuberances round the mouth. Sphaeronites punctatus, Foss. 33. f. 2, 
and Sph. munitus, f. 4, are common species at Bala ; and a fine species of Pleu- 
Fossils (33). Lowee Silurian Cystideans. 
L Echinosphserites 
Balticus, Eichwald. 2. 
Sphseronites punctatus, 
Forbes. 3. Ovarian py- 
ramid of Echinosphse- 
rites granulatus, M'Coy. 
4. Sphseronites (Caryo- 
cystites) munitus, Forbes. 
5. Sph. (Echinosphseri- 
tes) granatus, Wahl. 6. 
Agelacrinites Buchianus, 
Forbes. 
rocystites, a genus which has the two halves of the cup differently constructed, 
has been found in the Lower Silurian shales near Llandovery. One exceedingly 
rare and curious form, belonging to a different group from the others, and more 
resembling the Silurian genus Pseudocrinites in its structure, possesses arms, 
which are affixed like the spokes of a wheel on the upper surface. It has been 
found in North Wales, and is figured in the Memoirs of the Geological Survey ; 
it is represented above, Foss. 33. f. 6. Professor E. Forbes named this form Age- 
lacrinites Buchianus, in honour of that great geologist the late Leopold von 
Buch. 
Of Starfishes two species were discovered in 1844, by Professor Sedgwick and 
Mr. Salter, at Bala. One of these, Foss. 34. f. 1, described by the late Edward 
Forbes*, was thought by him to belong to the modern genus Uraster, so common 
on our own shores ; it appears, however, to be distinct, and has been named 
Palseaster t; the other was unfortunately lost when it had been ascertained to 
belong to the true Ophiuroid group, and named provisionally Ophiura Salteri, 
by Professor Sedgwick. It is probably a Protaster (see p. 127, & Chap. X.). 
Fossils (34). 
1 
Lower Silurian Starfishes. 
2 
1. Palseaster , 
obtusus, Forbes. 
From Bala and 
Waterford. 
2. Palseaster as- 
perrimus, Salter. 
From near Welsh- 
pool. 
Palseaster obtusus has since been obtained from the slates of Wales and Ire- 
land, and is represented in the preceding woodcut, together with a very distinct 
species from near Welshpool — P. asperrimus. 
Among the Shells of the mass of the Lower Silurian strata, above the lowest 
or ' primordial ' zone, Lingulse again occur, though of different species. Lingula 
attenuata, PI. V. f. 16, is indeed one of the most characteristic shells of the Llan- 
* Memoirs G-eol. Survey, Decade 1. 
t Ann. & Mag. Nat. Hist, for Nov. 1857 ; Rep. Brit. Assoc. 1856, Trans. Sect. p. 76. 
