NKBELA SCOT1CA. 61 



Since the above was written Playfair Las described 

 under the name of Nebela dentistoma var. hujeniformis 

 an Australian form which evidently belongs to this 

 species, but is somewhat larger, being 126/x in length. 



6. Nebela vitrsea var. sphagni Wailes. 

 (Vol. II, Plate XXVIII, figs. 14-17.) 



Nebela vitrsea 



PENARD (pars) Faune Rhiz. Leman (1902), pp. 372, 374, f. 6. 



CASH Brit. Fresliw. Rhiz. II (1909). pp. 121-122, pi. xxviii, ff. 14-17. 



WAILES & PENARD in Proc. R. Irish Acad. XXXI, LXV (1911), pp. 18, 



50-51, 60, 61. 

 Nebela-mtrwa var. sphagni 



WAILES in Jrn. Linn. Soc., Zool. XXXII (1912), pp. 125, 141. 



This variety is the Nebela ritrsea described by Cash 

 in Vol. II. It is a sphagnum-inhabiting species, much 

 smaller than the large deep-water form . described by 

 Penard, which is 1 70 ft to 200 /A in length ; in America 

 this large form is found in sphagnum, attaining nearly 

 300 p, in length, but its test is somewhat different in 

 structure from that of the Swiss type. 



N. vitrsea var. sphagni usually measures from 80 /x 

 to 100 /a in length, but may vary between 66 //, and 

 120 /a, and is very similar in size to N. dentixtoma, 

 with which species it is frequently associated in the 

 British Isles. The test differs from that of the type 

 by not being composed of regularly-arranged plates or 

 scales the interstices between which are mostly 

 covered by small overlapping plates ; the aperture of 

 the test also is bordered by proportionally smaller 

 and more numerous grains of irregular shape, which 

 in the type are usually only from seven to ten in 

 number. 



In Switzerland the large species is recorded only as 

 occurring in deep water and var. sphagni from one or 

 two localities, and even there it is rare ; but in America 

 the two are found in association amongst sphagnum 

 and aquatic vegetation in shallow water. 



Both in America and Switzerland a medium-sized 



