214 LAFOEIDJE. 



Genus FILELLUM, Hincks. 



Der. Dimin. offilum, a tliread. 

 KETICTLARIA, Wyvillo Thomson. 



GENERIC CHARACTER. Stem creeping, filiform, reticulate, 

 immersed in a chitinous crust ; hydrothecce tubular, decum- 

 bent, adherent, without operculum, irregularly disposed 

 along the stem, to which they are attached at the base or by 

 a short stalk ; gonotheca unknown. 



THIS genus was constituted by Prof. Wyville Thomson 

 under the name of Reticularia, which unfortunately had 

 been previously assigned to a group of Fungi, and there- 

 fore cannot be retained. 



I have not been able to satisfy myself as to the presence 

 of a crust involving the creeping stem, and have included 

 this character in the definition of the genus on the authority 

 of Prof. Thomson. 



F. SERPENS, Hassall. 



CAMPANULARIA SERFENS, Hassall, Zoologist, No. 69, 2223; Transact. Micr. 



Soc. iii. (1852) 163, pi. xxi. fig. 4. 

 CAPSULARIA SERPENS, Gray, Brit. Mus. Badiata, 151. 

 EETICULAUIA IMMEKSA, Wyville Thomson, Ann. N. H. (2nd ser.) xi. 443, pi. xvi. 



figs. 2, 3. 

 SERPENS, Hincks, Ann. N. H. (2nd ser.) xviii. 469 (1856). 



Plate XLI. fig. 4. 



STEM extremely delicate, forming an irregular network ; 

 HYDROTHEC^E oblong, with an even patulous rim, at- 

 tached for about two-thirds of their length, free and 

 curved upwards towards the aperture, sessile or with a 

 very short stalk, sometimes laid alongside the stem, and 

 sometimes forming an angle with it; GONOTHEC^: un- 

 known ; POLYPITES very minute, of a greenish colour. 



THIS is the common parasite of some of the larger Sertu- 



