58 REPORT—1852. 
pep a Wahl.? f.3 (O. spinulosus ?, Phill.), and Agnostus pisiformis, Wahl. Brongn. 
toate ke 
It is quite possible therefore, as suggested by M. de Barrande himself, that these 
shales may be identical with the black slates of Sweden, and belong to the Etage C. 
It should however be observed, in conclusion, that Agnostus in England is ge- 
nerally characteristic, not of the first, but of the second zone or true Llandeilo flags ; 
we have at least three species; also that the true position of our Paradowides is not 
known; that, in the probable equivalent of the ‘ Lingula Flags’ in S. Caernarvon- 
shire, an Asaphus, the Didymograpsus Murchisone, and perhaps Lingula attenuata, 
occur; that the genus Cruzjana, the fucoid described below, is characteristic of beds 
in Normandy*, which lie nearly in the place of our Caradoc sandstone ; and that Hyme- 
nocaris, the new genus here proposed, belongs to a group of Phyllopod Crustaceans 
not hitherto described from strata older than the Upper Silurian. Taking all these 
circumstances into account, it would, I think, be premature to pronounce as to the 
separate and distinct character of our own lowest fossiliferous zone; and it may 
perhaps be necessary hereafter to modify the conclusions drawn by so able and suc- 
cessful an observer as M. de Barrande as to the primordial and isolated character of 
his earliest fossil group; it may be a local, and not a general pheenomenon. 
It will be borne in mind that the lowest fossiliferous zone in England and Wales 
is not quite the oldest known. The purple and green schists of Wicklow in Ireland 
contain Zoophytes or Bryozoa (Oldhamia antiqua and O. radiata, Forbes), and they 
have been determined to occupy a similar place with the “ Llanberis slates and Har- 
lech grits” of Prof. Sedgwick, which underlie the ‘ Lingula flags,’ and which in Wales 
and Shropshire are void of fossils. 
Notes on the New Forms above mentioned. 
I append a short description of the new genus Hymenocaris, and the new species 
of fucoid, Cruxiana, from the ‘ Lingula Flags.’ 
Hymenocaris, new genus. 
Carapace ample, semioval, narrowed towards the front, curved downward at the 
sides, but not angularly,bent along the dorsal line; no external eyes; antenne? of 
two pairs, short and not visibly jointed ; abdomen as long or longer than the carapace, 
of 8 [or probably 9] transverse segments,—the last with short unequal appendages. 
Species 1. Hymenocaris vermicauda, Salter, Records Mus, Pract. Geol. ined. 
There are four, and may be more appendages to the last segment; for one crushed 
specimen shows two of them, a short and a long one on the dorsal part of the seg- 
ment, and two others toward the ventral edge; and it is impossible to say how they 
may have been arranged. 
The number of segments to the body is also not quite certain, though nearly as 
above stated. One specimen shows the 8 anterior, another the 4 or 5 posterior ones and 
the appendages. The antennz? too, are 3 appendages, two longer than the third, 
proceeding from the front of the carapace: they show no trace of joints. 
The genus is evidently related to the living Nebalia, and differs markedly from 
Ceratiocaris, M‘Coy, by the entire convex carapace, not bent along the dorsal margin. 
It has, too, a neck furrow running all along the posterior edge. There are no traces of 
eyes on the exterior of the carapace. The crust was very thin. 
Localities. Tremadoc; Dolgelly; North Wales. 
Cruziana, D’Orbigny. Frena, Marie Rouault. 
C. semiplicata, sp. nov. C. longa, plus pollice lata, linearis, integra, ad sulcum me- 
dianum crebriplicata, extis levigata: plicis obliquis, simplicibus aut irregulariter 
furcatis, ad marginem levem latum abrupte terminatis. 
It appears to differ from all the published species, in the smooth border, against 
which the oblique folds terminate abruptly ; they very rarely run out into it. The 
plaits are not always equal, and are sometimes branched and occasionally fasciculate. 
Locality. Carnedd Ffiliast, near Bangor, North Wales; Stiper Stones, Shropshire. 
* Marie Rouault, Bull. Soc. Géol. France, vol, vii, 1850, p, 725. 
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