OBSERVAÏIOlSfS ON THE EUPLECTELLID.Ë GENERALLY. 21 



Excellent as tliis diagnosis is on tl^e whole, I think it may 

 perhaps with advantage ])c somewhat remodelled in order the 

 more sharply to characterize the family. In fact, this seems 

 necessitated to a degree by the discovery of new forms since the 

 above diagnosis was drawn np. In attempting the revision, it is 

 to be borne in mind that of all the lyssacine families it is especially 

 the Caulophacidœ (for which, vide a later paragraph in this 

 Contribution), with which the Euplectellidse, as bearing closest 

 resemblance in certain important systematic characters, require 

 to be placed in contrast. Xow, the more important points not 

 indicated or explicitly mentioned in the aljove diagnosis F. E. 

 Schulze's but which appear to call for our attention here, seem 

 to be the following. 



1. The massive development of tlie body in JIalacosaccvs 

 florlcomatus Tops, and Placosoma paradictywi/ Ij., neither of 

 which can be said to be tubular, saccular or cup-like. 



2. The presence of a distinctly stalk-like part in the body 

 of JIalacosaccus florlcomatus, running out into a tuft of anchoring 

 spicules at the inferior end. The stalk is then a thing, the 

 occurrence of which is not confined to those Euplectellids which 

 at base are firmly fixed to the hard substratum. 



3. The EuplectellidcC, excepting a few insufficiently known 

 forms {JIalacosaccus vastus, 31. luiguiculatus, Hertwigia, Hyalo- 

 slyhis), as a rule exhibit on the parietes a large number of separate 

 orifices (oscula) for the discharge of water. It is connnon to find 

 them all (Ilolascus) or in part [Euplectella, Corhiteila, etc.) in close 

 congregation (forming the sieve-plate meshes) at the superior end 

 of the body, whereby is brought about a condition which simu- 

 lates such other cases as show a single hirge tei-minal osculum 

 with (e.g., Flacosoiita paradiclijuin) or without (e.g., JIalacosaccus 



