394 W. B. R. King— A New Trilobite. 



that they were the places where the muscles working the hypostome 

 were attached; or that they were ocelli. Moreover, the different 

 authors do not agree as to whether they were perforations in the shell, 

 or merely depressions. 



It may not be out of place here to add a few notes on these ' pores ' 

 as exhibited in the above -described species. The pores are situated 

 just in front of the eye-lobe, on the furrow separating the glabella 

 from the fixed cheek. The surface of the shell immediately 

 surrounding the depression is smoother than the rest of the glabella. 

 In well-preserved specimens the depressions appear as deep oval pits 

 in the shell, with their longer axes parallel to the length of the 

 glabella, When observed fi-om the under side the shell is seen to be 

 bent downwards to form a slightly hollowed cone. A section 

 through the pore shows that the shell is not perforated, but rather 

 thickened on the margins of the cone, while the inside of the cone is 

 flattish and rough. The shell forming the rim and inner portion of 

 the cone seems, however, to be of a different nature to the rest of the 

 glabella, being somewhat lighter in colour. This lighter portion also 

 forms the base of the upper funnel-shaped depression (Fig. 2). 



Fig. 2. — Section through pore just in front of the eye-lobe on the furrow 

 which separates the glabella from the fixed cheek. 



The function of these pores is difficult to decide; but the rough 

 surface of the under side of the cone suggests a place of muscle 

 attachment ; if this be so, it would agree with M. Barrande's con- 

 tention, but against this there is the difference in the ornamentation 

 of the upper surface and the change in the character of the shell, 

 which would seem to indicate the presence of some sense organ. 



In conclusion I have to thank Professor T. McK. Hughes and 

 Dr. H. Woodward for much help in working out the Trilobites, and 

 Dr. J. E. Marr, at whose suggestion I first visited Shunner Fell. 

 I have also to thank Messrs. A. W. R. Don and H. T. Kennedy, of 

 Trinity College, Cambridge, and Mr. E. Hodgson, of Hawes Junction, 

 for lielping me to collect the specimens. 



EXPLANATION OF PLATE XXXII. 

 Fig. 1. Free cheek and eye, showing facettes. x 5. 

 ,, 2. Almost complete specimen, x 2. 

 ,, 3. Eestoration of hypostome. X 5. 

 ,, 4. Eestoration. x 3. 

 ,, 5. Glabella of young specimen showing granulated surface and large 



lobes. P. position of ' pore '. x 5. 

 ,, 6. Side view of almost complete specimen. X 2. 

 ,, 7. ' Pore ' seen from the under side. X 20. 



Figs. 1, 2, 5, 6, 7 are photographs. 

 Note. — These specimens are now in the Sedgwick Museum, Cambridge. 



