ACTINOPODOÜS IIOLOTHUrJOIDEA. 



41 



Textfig. 9. 



Mesotfiurîa deanî : a-Cnlcareous ring ; b, c — 

 Tables of ventral perisome ; <1, e — Same of pedi- 

 cel, (c — ex 225). I — luterradialia ; R — Radialia. 



The animal in life clothes itself with sand grains, small shells 

 and shell fragments, which adhere by action of its numerous 

 pedicels. 



Witli the exception of 

 endplates wliieli are found 

 on the ends of the small 

 dorsal, the large lateral and 

 small ventral pedicels, there 

 is only one kind of calcare- 

 ous deposit, viz., the tables 

 {b — e). In the ventral peri- 

 some, tlie tables measure 

 from 0.07 to 0.10 mm. in 

 diam., and their spire 0.05 

 mm. in height. Spire 

 consists almost always of three pillars. It has generally only one 

 crossbeam. The crown has several teeth on the top of each of the 

 three pillars. No elongated diverging ends to the pillars as in 

 some species. Tables on the pedicels not different in shape, but 

 smaller in size, the disks measuring 0.05 — 0.07 mm. in diameter. 

 No supporting rods. 



Bemarks : — The fact that these specimens are without any 

 tentacular ampullae and that their two-branched respiratory tree 

 does not intermingle with the blood vessels of the alimentary 

 tract, at once puts them in the sub -family Synallactinae ; and the 

 presence of only one genital bundle on the left side makes them 

 referrable to the genus Mesotlmria. Even in the narrowed definition 

 of tlio genus given by Perkier, the presence of pedicels on the 

 odd ventral ambulacrum fits them to that genus. The speci- 

 mens have tables of the triradiate type and are very close to M. 



