248 MYRIOZOID^E. 



little below the mouth ; a small raised avicularium on 

 each side of the orifice, almost in a line with the lower 

 margin ; mandible acute, directed obliquely downwards 

 or straight across, sometimes replaced by a large central 

 avicularium, pointing upwards. Ocecium globose, pro- 

 minent, somewhat flattened in front, and thickly punc- 

 tured; frequently a large avicularium at the back of 

 it, placed transversely. 

 Colonies forming large rose-coloured crusts. 



Var. a (hastata, Hincks). Orifice with a broad, shallow 

 sinus on the inferior margin; immediately below it a 

 tall, sharply pointed mucro, expanded at the base, 

 tapering towards the apex, bearing on one side or the 

 other at the bottom a large avicularium, with a pointed 

 mandible directed upwards ; surface thickly covered 

 with rather large punctures and intersected by ridges, 

 which are sometimes arranged in radiating fashion. 

 (Plate XXXIII. figs. 10, 10 a.) 



Var. yS (mamillata). Zooecia tumid, irregularly disposed; a 

 single avicularium immediately below the oral sinus, 

 borne on a mamillary enlargement of the front wall; 

 mandible directed straight outwards. 



Var. 7 (nitida) . Zooecia much more elevated than usual, 

 bright and lustrous, the front wall ascending towards 

 the large and massive mucro, from which ridges radiate 

 towards the sides, anastomosing, and rising into many 

 nodulous processes ; an avicularium on each side of the 

 mouth, pointing obliquely outwards. 



Var. B (crucifera, Norman). "With a central, suboral 

 process rising from the cell in the form of a very long, 

 gradually tapering, rugose, perpendicular spine, which 

 is more than equal to the length of the entire cell, and 

 in its most perfect state gives off a branch at nearly 

 right angles at rather more than half its length, so that 

 the whole process is in the form of a cross or trident." 

 Sometimes a branch is developed near the base of the 

 mucro, and a second towards the upper extremity. 



