368 ESCHARID.E. 



MUCRONELLA LAQUEATA, Norman. 



Plate LI. fig. 8. 



LBPRALIA LAQUEATA, Norman, Ann. N. H. January 1864, 85, pi. x. fig. 5. 

 DISCOPORA COCCIXEA, forma OVAUS (part.), Smitt, 1. c., pi. xxyii. fig. 176. 



Zouecia rhomboid, broad, not produced below, very slightly 

 convex, granular, bordered by raised lines', and with a 

 row of large punctures round the base; orifice semicir- 

 cular ; peristome not raised, lower lip almost straight, 

 pouting, a broad denticle deeply set within it ; marginal 

 spines three. Ooecia round, subimmersed, granular, 

 punctured round the margin. 



Colonies tinged with red when living, ivory white when 

 dead; the surface dull. 



HABITAT. On stones from deep water. 



LOCALITY. Shetland, 80-100 fathoms; the Minch, 

 Hebrides (A. M. N.) : coast of Antrim (Hyndman) . 



GEOGRAPHICAL DISTRIBUTION. Bergen (A. M. N.) : Arctic 

 Seas (Smitt). 



This species is a critical one, and perhaps approaches 

 M. variolosa too nearly. It most markedly differs from 

 it in having the cells much less elongated and much broader 

 in proportion to the length, in being always reddish when 

 living, and ivory-white when dead, and destitute of the 

 shining surface which characterizes the last-named species. 

 There is some difference, too, in the form of the mouth, 

 which is wider and less arched (with less space between 

 the upper and lower margins) than in M. variolosa. The 

 lower margin is turned slightly outwards ; though some- 

 times mucronate, the mucro is a much less constant and 

 striking feature than in the allied species. The denticle, 

 which is of great breadth, is very deeply planted within the 



