410 ME. F. B. COWPEK EEED ON THE [Aug. 1 896 



cheeks and glabella by a neck-furrow. The posterior border of the 

 head-shield is not straight, but formed of three gentle backward 

 curves — the lateral ones bounding the neck-segment behind the 

 cheeks and the middle one the neck-lobe of the glabella. 



The whole surface of the cheeks and glabella is finely punctated, 

 Affinities. — The two points of difference already given distinguish 

 this species from A. tumidus, to which it seems otherwise allied. 

 A. (Raphiophorus) clepressus of Angelin is distinguished by the 

 smaller size of the circular basal lobes, their greater distance apart, 

 the shortness of the glabella, and its practical non-carination. 



TlRESIAS INSCTJLPTUS, M'Coy. 



This peculiar trilobite is apparently allied to Ampyx, as M'Coy 

 says. It is very rare in the Kildare Limestone, and I have only 

 seen one specimen from the Keisley Limestone, and that is in the 

 Carlisle Museum. 



In M'Coy's figure 1 there are two small indentations near the 

 base of the glabella, but they are not mentioned in his description, 

 nor are they seen in the Keisley specimen. The last-named shows 

 that the cheeks are prolonged as a narrow flattened band in front 

 of the glabella, but there is no true border to the head-shield. 

 The axal furrows are also wider than M'Coy figures. The wavy 

 thread-like lines which ornament the glabella are roughly con- 

 centric to its front end, and those on the triangular convex cheek 

 are roughly parallel to the lateral edge of the head-shield. The 

 other features are given in M'Coy's description, and need not be 

 repeated. 



Length of head-shield 9*5 millim. ; width (estimated) of the 

 same at the base 14-0 millim. 



Olenid^:. 



Kemopletjrides Colbii, Portl. 



There are two beautifully-preserved thoracic rings and pleurse in 

 the Woodwardian Museum, showing the characteristic ornamenta- 

 tion of the species with great distinctness, but no other portion of 

 this trilobite is known. 



Hemopleurides lotstgicostattjs, Portl. 



In the collection made by Messrs. Marr and Nicholson from the 

 Keisley Limestone there is an exceedingly fine head {minus the free 

 cheeks) of this species, showing the ornamentation most distinctly. 

 Salter's description (Mem. Geol. Surv. dec. viii. text with pi. viii. 

 p. 9) makes any further remarks on my part superfluous. The 

 species also occurs in Prof. Harkness's collection at Carlisle. 



Ctphonisctjs socialis, Salter. 



The head-shields of this peculiar little trilobite are not very 

 common at Keisley. Nevertheless I have found several there 



1 M'Coy, ' Syn. Silur. Foss. Irel.' pi. iv. fig. 1, p. 43. 



