40 CARBONIFEROUS TRILOBITES. 



cheeks deeply furrowed and smooth, with a raised margin having a rounded rim ; 

 neck-lobe narrow, smooth, flattened, and separated by a rather strongly marked 

 neck-furrow, which is continued and unites with the furrow surrounding the free- 

 cheeks, forming somewhat blunt angles to the head-shield. 



Formation. — Carboniferous Limestone. 



Locality. — Settle, Yorkshire. 



Only the head of this rather large species is known, but it differs in many 

 respects so markedly from its nearest ally, G. seminifera, that I feel justified in 

 making it a distinct species. 



The glabella is broad and rather obtuse in front and very narrow behind ; the 

 basal lobes are small and drop-shaped ; the eyes are very small, placed far back on 

 the cheeks and near the basal lobes ; the granulations on the head and cheeks are 

 coarse and closely placed, and suggested the specific name. Along the anterior 

 border of the head these granulations are elongated, and form a close and regular 

 marginal ornamentation (see PL VII, fig. 11). There are five specimens (all 

 detached heads) of this species, from the Carboniferous Limestone of Settle, 

 Yorkshire. They are all preserved in the Woodwardian Museum, Cambridge. 



18. Griffithides glaber, H. Woodw., sp. nov. PL IX, figs. 4 a and 4 b. 



I am indebted to Mr. B. T. Newton, F.G.S., Assistant Naturalist to H.M. 

 Geological Survey of Great Britain, for drawing my attention to this new and 

 interesting form of Carboniferous Trilobite, which I had not observed in the 

 collection on my former visits to the Museum of Practical Geology, Jermyn 

 Street. 



Both the specimens figured are preserved in a dark crystalline rock from the 

 Carboniferous Limestone, Castle-Mumbles, Glamorganshire. The extreme length 

 of the more complete specimen (fig. 4 a) is 36 mm., and its greatest breadth 

 13 mm. Length of glabella, including neck-lobe, 12 mm. ; length of pygidium 

 13 mm. The head is much mutilated, but sufficient of it remains to show that 

 the glabella was smooth, rather tumid, longer than wide, with a basal-lobe on 

 each side near the neck; neck-lobe moderately broad, and marked with one 

 central tubercle ; the eyes are not preserved ; border of free-cheek terminating in 

 a short lateral spine on each side, and striated below. Free thoracic somites nine 

 in number ; extremities of pleuraB smooth and truncated ; axis rather wider than 

 lateral portion of somite ; coalesced abdominal somites about nine in number ; 

 axis nearly smooth, with a slightly serrated posterior edge to each body-ring, 



