258 SIDNEY F. HARMER. 



the seaweed, and measures about 20 mm. iu lengtli by about 

 6 mm.; the orifices are on the outer side of the collar; (b) 

 slides which have been prepared from this specimen. 



This species cannot well be confused with any other ; the 

 great auriculate median process (fig. 8), uniting distally with 

 the condyles, the four strong opercular teeth (fig. 24), and in 

 particular the immense sub-basal sclerite, make this species 

 one of the most distinct which I have had the opportunity of 

 examining. 



The edge is hardly raised. The post-oral shelf is deep, 

 massive, and tubercular, being well developed even proxi- 

 mally. The oral shelf is narrow and smooth. The condyles 

 are long, and meet the distal border of the median process, 

 projecting as well-defined points into the distal chamber of 

 the zooecium. The oral arch is thick and not much raised. 

 The cryptocyst is sharply separated from the post-oral shelf, 

 and its horizontal portion is nmch depressed, tubercular, and 

 (when old) with small pores. It slopes very steeply but 

 without angulation into the cavity of the median process. 

 The tube is incomplete distally, its low lateral walls joining 

 the distal (or basal) wall, by which the tube is completed. 

 The cryptocystal boundary of the lateral recesses is nearly 

 vertical. The back is tubercular, and is too thick to be trans- 

 parent. It is covered by a thick epitheca, which is con- 

 tinuous with a chitinous layer that separates the vertical 

 calcareous walls of adjacent zooecia, and is itself continued 

 into the epitheca of the free surface. The uncalcified part 

 of the vertical wall being relatively thick, some of the zooecia 

 of an incinerated specimen appear completely separated from 

 one another laterally, each having its own wall. The epitheca 

 is thin and the epithecal sclerites are long, and start from 

 the operculum, b zocecia have not been observed. The A 

 opercula (fig. 24) are very strong, broader than long, with 

 four great teeth on the main sclerite and an enoi-mous sub- 

 basal transverse sclerite between the two proximal teeth. 

 When seen from above, in a dry preparation, the opercula 

 show a specially dark line at g, aud another, not quite so 



