DIAGNOSE« OF THE SPECIES. 291 



spicules may safely be taken for the scleroblast-iinclei. The 

 nuclei in (|uestion occur in this position constantly in all such 

 spicules as are apparently still growing and also for some time 

 after these have attained full dimensions. As viewed in an 

 equatorial optical section of the sjiicule the said nuclei are seen 

 to be four in number, one situated in each of the four angles 

 formed by the short principals. In certain cases these particuhir 

 nuclei were found to l)e somewhat larger than others lying close 

 beside them. For the present I can defmitely say nothing 

 more aljout the matter. 



DIAGNOSES OF THE SPECIES TREATED OF IN THIS 

 CONTRIBUTION. 



Genus LANUGINELLA O. ScHM. 



L, jmi>n O. SCHM. — Small, spheiical or ovoid, lirndy at- 

 tached at base ; with a small, smooth-edged osculum leading into 

 a nearly tubular gastral cavity. External surface smooth or 

 covered with a veil formed of small j^i'ostal pentactins. Aper- 

 tures of excurrent canals not covered by gastral layer. Dermalia, 

 rough stauractins. Gastralia, regular oxyhexactins. Hexasters 

 consist of discohexaster and stroljiloplumicome. Discohexaster, 

 varying in size but under iUO /'• dia.; spherical ; each short 



