292 THE ALGA-FLORA OF CAMBRIDGESHIRE. 
312. N. picepsata Ehrenb. 3. Ditch, St. John’s College ‘‘ backs, 
Cambridge 
313. N. eLuiptica Kitz. Syn. N. ovalis W. Sm. 2. Dernford 
Fen, 1 mile S. of Shelford. 8. Sheep’s Green, Cambridge; Com- 
berton. 5. Wicken Fen; Chippenham Fen 
314. N. Tuscuna Ehrenb. 5. Charpenhast Fen. 
815. N. pusitra W. Sm. 8. Sheep’s Green, Cambridge. 
316. N. cuspmata Kiitz. 2. Shelford. 38. Ditch, St. John’s 
College ‘‘ backs,” and Sheep’s Green, Cambridge. 4. Histon. 5. 
Wicken Fen. 7. In ponds, March. 8. Guyhirne. 
317. N. amsicva Ehrenb. 4. Histon. 6. Sutton. 7. Near 
March. : 
318. N. spHmropnora Kiitz. 8. — Park. 5. Wicken 
Fen. 6. Near Ely. 7. Ponds 8. of March. 
319. N. exis (Kiitz.) Grun. 3. Bk eep’s Green, Cambridge ; 3 
Trumpington ; tanec Lord’s Bridge; Wimpole Park. 5. 
Bur ce Wicke 
. N. Ampuispana i Boe. Shelford. 8. Ditch, St. John’s 
Collese “ backs,”’ rig a Wimpole Park. 
7. Near March; Sutton West Fen. A tate re is “given A two auxo- 
sais of this species produced by conjugation Sei 895, fig. 9). 
ar. GIBBERULA (Kiitz.) Van Heurck. Syn. N. _giibernl Ps 
3. Din St. John’s College ‘backs,’ and Sheep’ 8 iti oe 
bridge. 5. Wicken Fen; Chippenham Fen. 6. Sut 
22. N. ripis Ehrenb. Syn. N. firma W. Sm. of be 
PHIGOMPHUS (Ehren) Van Heurck. Syn. N. amphi- 
5 ee Ehren b. 5. Wicken 
ewe = ) De Toni. Syn. N. amphirhynchus 
Ehrenb. 5. Wic 
Var. arrinis (Ehrenb.) _ Heurck. Syn. N. afinis Bhrenb. 
8. Sheep’s Green, Cambrid 
*323. N. Pupuza Kiitz. ‘ Sheep’s Green, So: Wim- 
pole Park. 4. Histon. 5. Wicken Fen; Chippenham Fen. 
*324. N. aromores Grun. 8. Comberton; ants Park. 
325. N. Gaurica (W. Sm: Bie Van Heurck. Syn. Diadesmis Gallica 
we ie - a 
URCKIA RHOMBOIDES (Khrenb.) Bréb. var. sAXONICA 
(Ra i a ‘e ‘Sy Frustulia sawonica Rabenh. 1851; Macchia crassi- 
nervia wep ee Chippenham Fon 
327. AmpHirpLeura petiucrpa Kiitz. 8. Sheep’s Green, Cam- 
bridge ; Winnpele Park. 5. Wicken Fen. 8. Guyhirne: very 
sean in some ponds by the railway station, Aug. 1898. 
328, UROSIGMA aTrenvatum (Kiitz.)Grun. 2. Dernford Fen, 
1 mile S. = Shelford. 8. Ditch, St. John’s College ‘‘ backs,’ 
