BARRANDIA. 



179 



"Barrandia (Homalopteon) longifrons, Ed(/ell. Woodcut, fig. 42. 



Fig. 42. 



" B. {Homalop.) magna, 4 uncias fere long a ; cui glabella protlucta claviformis^ 

 oculi propinqid {sulcus cervicalis abest?). In thorace axis latitudo dimidium latitudinis 

 pleurarum, quarum sulci pane aciem attingunt, efficit. Cauda semiovata axem conicum gerit, 

 dimidium longitudinis illius efficientem ; latus quodque sulco unico furcato distinctum. 



" A veiy large species, with a projecting club-sbaped glabella ; the axis of the thorax 

 about half the Avidth of the pleurae ; and the tail semicircular or rather semi-oval, each 

 side bearing one strongly branched furroAv only. 

 The long clavate glabella, with undulated sides cor- 

 responding to the glabella-furrows, projects about one 

 third of its whole length beyond the anterior margin 

 of the cheeks, which are at their base one third wider 

 than the base of the glabella. The rather large eyes 

 are placed considerably forward and close in to the 

 glabella. The fixed cheek is very broad, and the facial 

 suture curA^es widely out beneath the eye, so that the 

 free cheek is much narrowed, its outline arched almost 

 in a semicircle ; it has a narrow but very distinct 

 margin ; it shows, so far as our only specimen can be 

 trusted, no neck-furrow (the fi'ont thorax-ring has been 

 pushed under the head and appeared to us at first sight 

 as a branched neck-furrow), the cheek ends pos- 

 teriorly in a small needle-shaped head-spine. 



" There are, apparently, seven thorax-rings, as in 

 some other species of this genus. The pleural furrow 

 is well defined, and reaches almost to the tip of each 

 of the recurved flat pleurae. 



" The tan, fig. 43 (natural size and enlarged), found in the same locality, is supposed 

 to belong to this species, as only one other Barrandia 

 (B. Cordai, M'Coy, a small species) is known to occur 

 there. The length of this caudal portion is almost 

 equal to its breadth ; the axis is conical, the base 

 being about half the length. The side has two 

 furrows, or perhaps a strongly branched one (the 

 branch arising as usual from the very base, and 

 indicating the suture of the first tail-segment) : these 

 nearly reach the outer margin ; but no corresponding furrows occur on the smooth conical 

 axis, which is half the length of the whole tail, and ends apparently in a sharp tip, from 



Barrandia (Homalopteon) longifrons, Edgell. 

 Llandeilo Slates, Pembrokeshire. Mr. H. 

 Wyatt-Edgell's Cabinet. 



Fig. 43. 



Tail of B. (Homal.) longifrons ? Llandeilo 

 Slates, Pembrokeshire. From the same 

 Cabinet, a, Natural size ; li, enlarged. 



