BARRANDIA. 139 



hung by it. For nearly two thirds its length it is marked by four lateral farrows, irregular in 

 direction, which divide it into four lateral lobes, exclusive of the forehead- and neck-lobes. 

 The furrows reach far inwards, leaving only a narrow median space unoccupied. The 

 front ones are straight across, the second pair curve from without downwards, the third is 

 a short deep impression, the fourth or lowest pair are nearly straight, but so oblique towards 

 the narrow neck-furrow as to separate a pair of triangular lobes. None of the furrows 

 reach the outer margin. 



In the Decade, from which this description is partly drawn, I have inaccurately described 

 the lower glabella-lobes as part of the neck-lobe. It is not so. There are four pairs of 

 lobes to the glabella.^ 



Eyes rather large, placed very high up towards the termination of the facial suture on 

 the margin. The eyelid semilunate, but not constricted above or below. The facial 

 suture is nearly vertical above the eye, and below it turns very little outwards, cutting the 

 posterior margin at about half the cheek's width. Free cheeks moderately large, with a 

 narrow border and a small spine. Labrum with the centre gently swelled, and with 

 concentric furrows and the usual pair of tubercles. The apex is broken off ; it was probably 

 obtusely pointed. 



Thorax with a broad axis, not quite so wide as the pleurae, and tapering backwards. 

 The rings are nodular, with bilobed tubercles on the sides, the hinder rings with a central 

 tubercle ; but all rather faintly marked. The pleurae are directed backward, and are some- 

 what sigmoid in outline ; the fulcrum rather faintly marked at about half-way along them. 

 The divisions between the pleurae are not nearly so conspicuous as the oblique furrow that 

 reaches nearly to the end of each, separating a broad and rather tumid posterior portion. 

 The tips are recurved and pointed, the foremost ones, perhaps, not quite so strongly as in 

 our large figure ; the hinder ones more so, as in fig. 6 a. 



Tail a semicircle, with the upper angles rounded off; the axis hardly more than two 

 thirds the length, flattened, conical, the ends a little pointed. There are about five distinct 

 ribs on the axis, each obscurely trituberculate. The axis is most convex behind ; it reaches 

 two thirds down the tail, with a rather large terminal portion connate with the triangular 

 appendix, making the axis a pointed one (see fig. 8). Lateral furrows four or five, very 

 oblique and short, the upper ones reaching two thirds — the lower not half across the broad 

 striated limb. The three upper ones (see fig. 8) are strongly duplicate throughout. 



Whole surface of tail covered with a concentric lineation, which runs across the limb 

 transversely, not parallel to the margin. The striae are continuous, but mixed with 

 smaller interrupted ones. The incurved caudal fascia is very broad, but its margin is not 

 distinctly seen. An equally broad fascia runs all up the pleurae, the sharp lineation crossing 

 them at right angles. We do not know the striae on the head ; but the labrum is strongly 

 and coarsely striated (fig. 9). 



' Oyyyia, Niobe, t'ne present genus, and Cromus, a Bohemian form, are examples of this large number 

 of glabella-segments. But it is extremeJy rare in the Triiobite group. 



