486 Dr. H. Woochcard — Neio Carboniferous Trilohites. 



than one-third the entire length of the animal ; the presence of a 

 tubercle on the axis of the neck-lobe of the glabella, and the 

 rounded form of the pygidium. The border of the head-shield is 

 semicircular, with a broad rounded margin ; the glabella is some- 

 what expanded in front, and the facial suture curves away from the 

 glabella outwards before it intersects the frontal margin. The eyes 

 are rather large, but are only faintly shown in Figs. 4 and 5, not 

 being well preserved in the soft shale. The axis of the thorax is 

 broad, being rather more than a third of the whole breadth of the 

 body, and is separated by a distinct and straight furrow from the 

 pleurae on either side. The body-segments, which are nine in 

 number, are straight and smooth, and have rounded extremities to 

 their pleurEe. The outline of the pygidium is rounded, with a 

 smooth and narrow margin ; the axis narrows rapidly to its 

 extremity and appears to consist of about eight coalesced seg- 

 ments, but these are only faintly indicated. The extremity of the 

 axis reaches nearly to the outer edge of the border of the pygidium. 

 The two nearly entire specimens figured (Figs. 1 and 3) are each 

 of them 12 millimetres in length. 



Compared with Philli'psia Eichwaldi,^ the species it most nearly 

 resembles, JPh. van-der-Grachtii agrees with it in the possession 

 of long cheek-spines, and in the presence of a median tubercle 

 on the axis of the neck-lobe of the glabella. It differs from it iu 

 the absence of any furrows on the glabella. The segments of the 

 cephalothorax agree with those of Fh. Eichwaldi, but the pygidium 

 differs greatly in outline, and also in the number of coalesced 

 segments. The margin of the pygidium in Ph. Eichwaldi is broad 

 and smooth, and ornamented with fine parallel lines or' stri^, 

 but in Ph. van-der-Grachtii the border is narrow and much more 

 rounded in outline. The axis of Ph. Eichwaldi shows distinct 

 evidence of the coalescence of 16 segments, whilst Ph. van- 

 der-Grachtii does not show more than 8 coalesced segments.^ 

 Ph. Eichwaldi measures 25 mm. in length, or double the size of 

 Ph. van-der-Grachtii. 



The only other species besides Ph. Eichwaldi which might be 

 compared with Ph. van-der-Grachtii are Ph. Leeii and Ph. minor, 

 from the Culm-measures of Waddon Barton, near Chudleigh, Devon- 

 shire, but the cheek-spines are not so long, and the pygidium is 

 more pointed and consists of about 14 coalesced segments. 



I have much pleasure in dedicating this species to Mr. William 

 van Waterschoot-van-der-Gracht, an old student at Stonyhurst, who, 

 as already mentioned, accompanied the Eev. G. C. H. Pollen in his 

 geological rambles along the banks of the Hodder, and also collected 

 many of the specimens here referred to. 



1 See Mon. Pal. Soc. Carb. Trilob., 1883, p. 22, pi. It. 



^ It is probable tbat this interesting little species may hereafter prove to be an 

 immature form of some larger Trilobite, at present unknown, from these beds. 

 Meantime it seems more convenient to treat it as distinct, and to describe it as we 

 have done. Numbers of this little form have been found on a slab in close proximity 

 to one another. 



