236 DESCRIPTION OF [Polyyastrica. 



is not. Two openings only are seen : these are central. 

 In some a canal seems to run from one end to the other. 

 Ova cluster yellow-green. 



346. NAUNEMA simplex (Shizomema, Ag.) The simple 

 Naunema. Lorica oblong, rounded at the ends, and 

 smooth, resembling N. arbuscula. They are disposed in 

 a simple series within flexible filiform tubes. Found 

 upon Ceramium hyalinum, and other sea-weed. Length 

 1-1 150th to l-570th. 



347. NAUNEMA Dillwynii (Mortema, Grev.) Lorica 

 oblong, Navicula-shaped, small, rounded upon the dorsal 

 and ventral surfaces, and densely arranged in many series, 

 within simple branched tubes. This species is always 

 firmly attached. Found in salt-water. Length 1 -2300th 

 to 1-1 150th. 



348. NAUNEMA Hoffmanni. Lorica small, Navicula- 

 shaped, and smooth ; numerous and dense within branched 

 tubes. Found in brackish water. Length 1-1 150th. 



349. NAUNEMA arbuscula. The tree-like Naunema. 

 Lorica robust, striated, and Navicula-shaped; numerous 

 and dense within erect fruticose tubes. Length 1 -860th. 



350. NAUNEMA Balticum. Lorica long, narrow, 

 striated, Navicula-shaped. Fly. 207 represents a portion 

 of a gelatinous tube surrounding several. They are 

 numerous and dense within flexible branched tubes, which 

 are tufted. Found in salt-water. Length 1- 860th. 



Genus LXXVI. GLOCONEMA. The tube grain Animal- 

 cules contain only one species, which is not figured by 

 Ehrenberg. It has a double envelope, the inner one, or 

 true lorica, curved and siliceous ; outer one combustible, 

 tubular, often branched, and containing many individuals ; 



