372 CONTlUBrTTOKS FEOM THE NATIONAL HERBAEIUM. 



open to question; for asido from its mod(j of growLli^ which may be noglecLutl, IL offers 

 a general distint litm in having ita raphe stop short of the apices of the frustuh^ aii<l in 

 its terminations being peculiarly bent. BuL tliese qtiahties are very inconstant, 

 and by an examination of many t=pecies it is made certain that no distinction is j)o?;sil)le 

 b<*tween it and thti members of the genus Oocconema. Syncyeha Ehrtmb. is even 

 more strikingly dissimilar in its mode of growtli, Ihe frustules being embedded in 

 gelatinous masses and grouping themselves therein l)y division into cylindrical com- 

 munitie?, whonc(^ the name. So far as the figures are concerned, they also slunv some 

 dissimilarity from the present genus in their strongly truncate (^nds,« but lliis must 

 bu looked upon as of htLh- significance when we compare them with the drawings of 

 tlie evident Coccouema''^ in Pritchard. It is, therefore, best to ignore in the foregoing 

 four genera their differences of attachment and unite them in a single genus. 



Cocconema inaequale (Ehrcnb.) Mann. 



Navkala inacqiialls Ehretd), Ber. Akad. Wiss. Berl. 1836: 5M. 1837, nom. nnd.; 

 Infus. 18 J. pL LLf. IS. J 838. 



Cymhdla chrcnhcnjii Kiitz. Bacill. 70. pL G.f. IL IS44. Pritcli. liist. Infus. ed. 4. 

 875. j)l. 7./. -?^;, pL .9./. ir>4A. 18(ii. Schmidt, AlUis pi 9. J, G f), 16^18, pi 71 J, 

 74, SO. 1875. Griff, ct Ilenf. Micr. Diet. cd. 3. pL IJ.f. SI, 1875. W. Smith, Synop. 

 Brit.Diat.l: 17. />/. .^ /..>/. 1S58. Van Ilt'ur. Synop. GO. ^j/. .^/ 7 .MSSl. H. L, 

 Smith, Sp. Dial. Typ. no. 117. ]874. Ibun, Diat. Alp. 5!K pi ^\ /. 40. 1880. 

 Cleve, Sv. Vet. Akad. llandh 26- : lti5. ISOl. ])e Toni, Syll. Alg. 2: 341). 1891, 

 Wolle, Dial. N. A. pL 7 J. S, 21, 25. 1890. 



SiaumneuinucqfuiJiti T^lircnb. Mikrog. pi 16. I.f. G. 1854, 



rimiuJaria inacquaJis Klucnb. ^Mikrog. pi Ul. ILf. G. 1854. 



Cywhdla (Irlirata Sclunidl, Atlas pi 9.f. 17. 1S75. 



Kut/iiig recogni/(\s the identity of Ins f(trm and I^lir(^nb(M*g's Xaiicula innrqKalis. 

 Il is possible Stannmns inacqifalts Eln-cidi. and Pinnnlana uiarqiial'.s Klu-cnl). can be 

 assigned to some otlicr spfM'ics as well as to this, as their exact character is rather hard 

 to determine. I^ul iht^y agree faiily well witli this species; and it is probable Ehri'U- 

 berg looks upon them as th(^ same, as he uses the three generic names interchang(^abiy. 

 In fact, the name Staurom:is Ehrenb.f^ is probal)ly a misprint, for the form shows no 

 trace of a stauros. 



Found at station 3013II, ILuvaiian Islands. 



Cocconema kamtschatica (Grun.) Mann. 



Cymhella hwdm-halica Grun.; Schmidt, Atlas pi lu.f. SI. 1875. Wolle, Diat, N. A. 

 pi 7./ ;/. 1890. Moll, types 3, 2, 10. 



Cleve'^ makes this a variety of Toccont^ina mciicayiuvi Ehvenh.e De Toiii,/i)n the 

 other hand, places it as a variety of Cymhella yadroidoi Kutz. Both of these resemble 

 the above. In fact, few species of this genus have hard and fast boundaries; and we 

 might add to the above resembling forms Cymhella maculala Kiitz., especially as figured 

 by Van Ileurck.i/ I, however, think that Grunow's form, on account of its smaller 

 size than in lheabov(^, its finer markings, its blunt apices, and its breadth at the middle 

 of th(^ valve, together with its tmnid outline on the ventral side, can be safely left in a 

 species by itself. 



Found at station 2882, off Oregon. 



«Cf. Pritch. Hist. Infus. ed. 4. pi 7./. 53. 18GL 



^Pritch. op. cit. pi 14- f. 18-20. 



cEhrenb. Mikrog. pi 16. I.f. 6. 1854. 



^Sv. Vet. Akad- Ilandl. 26: 177. 1894. 



€ Cf. Ber. Akad. Wiss. Berl. 1844: 342. 1845. Ehrenb. Mikrog. /)/. SS. VII. /. 6-7, 



1854. Schmidt, Alias pi 10. f, 32-S3, pi 71. J. 82. 1875-8L 

 / De Toni, Sylh Alg. 2: 362. 1891, 

 f/ Synop. pi 2. J. 16. 1881. 



