304 F. R. Cotcper Reed — Undcscrihed Trilohites. 



and unite in the middle at a distance from the neck-furrow equal to 

 the width of the occipital ring, thus forming a broad U-shaped 

 groove across the glabella. The furrows of the anterior pair have 

 a similar wavy backward course parallel to the posterior paii', but 

 they meet in the middle at an acute angle in a broad V instead of U 

 at a point situated at just half the total length of the glabella. The 

 outer ends of both pairs of furrows, particularly of the posterior pair, 

 curve backwards just before reaching the axal furrows, and diminish 

 considerably in strength. 



Frontal lobe of glabella subtriangular in shape and large, 

 being just half the length of the glabella. Neck-furrow nearly 

 straight, marking off a rather broad occipital ring of regular width 

 ornamented with a small median tubercle, and divided obscurely 

 into three portions by two faint oblique arched furrows arising from 

 the posterior angles and meeting in the middle on the neck-furrow. 

 Eye rather small, equal in length to the width of the middle glabellar 

 lobe; situated just opposite or a little in front of this lobe, a short 

 distance from the axal furrow and near the front end of the glabella, 

 with which it is connected by a weak ' eye-line.' 



Facial sutures cut the front margin of the head-shield at angles of 

 rather more than 60°, and at a distance apart of about one and a half 

 times the width of the glabella. From the point of section each 

 suture takes a backward and inward course in nearly a straight line 

 to the eye, round the projecting lobe of which it sweeps; thence 

 it bends obliquely backwards in a weak outward curve to cut the 

 posterior margin of the head-shield at an angle of about 45° and 

 at a distance from the axal furrow nearly equal to the basal width of 

 the glabella and at about two-thirds the distance to the genal angle. 



Border present round the anterior edge of the head-shield, of 

 moderate width and rounded, marked off by a distinct marginal 

 furrow. Neck-ring behind the fixed cheeks about equal in width 

 to this anterior border, but only half the width of the occipital ring. 



Free cheeks (shown in the specimen from Craig y Dinas attached 

 to a portion of the middle-shield) roughly triangular in shape, 

 and furnished with a short straight genal spine less than half the 

 length of the head-shield and directed slightly outwards. 



Thorax, incompletely known. Only ten segments are preserved 

 in our specimen from Moel Grou, two of these being attached to the 

 head-shield and separated from the rest of the body by a space of 

 7 mm. in length, which is equal to about five segments. It is clear 

 from an examination of the specimen that this space was originally 

 occupied b}' segments of the body which are now missing, for the 

 axis of the second segment attached to the head is nearly one and 

 a half times as wide as the axis of the first segment of the detached 

 posterior portion, and the two portions did not thei'efore fit together. 

 There does not seem to have been any movement or separation of the 

 two portions of the specimen, for if the axial furrows of the anterior 

 part he continued in their course backwards across the gap they 

 are found to exactly meet those of the posterior part and to preserve 

 the regular tapering of the axis. We may therefore conclude that 



