KONGL. SV. VF/r. AlvADKMlKNS IIANDLINGAH. HANI) 26. N:() 2. 73 



teristics as those of Ncidium, and also the longitudinal keels oi" ridges, but th(i strneture differs 

 entirely from that of Ncidium and agrees with that of IHploneis. In my f)])inion this remarkable 

 form ap])roaches nearer to Scot, latestriafa than any other. 



Gomphoneis Cl. N. Gen. 



Valve elongated, elavate, or asymmetrical with the transverse axis. Median line sti-aight, 

 more or less obli(iue. Terminal fissures straight. Axial area narrow, linear. Central area small, 

 rounded, with one or more stigmas. On both sides of the median line are longitudinal lines. 

 Structure double: slightly radiate costai, and fine puneta, forming obliquely decussating lines. — 

 Zone broader in the upper than in the lower end, not complex. Cell-contents unknown. 



I have formed this new genus for some species formerly considered as belonging to (TOmpho- 

 nema, but differing from it both in the structure and in the presence of the longitudinal lines. In 

 these characteristics they agree neai'ly with Scoliotropis, but differ in the sti'aight median line, and 

 the asymmetrical form of the valve. 



To Gromphoneis may perhaps also belong (roinji/ionema crirnse (tRUN. 



The few known species of (lomphoneis ai'e all of fresh-water habitat and are found iu North 

 and Central America. 



Artificial Ivi/. 



^ I Ot'iitral ar(?a on lioth sidt^s of the central nodule with i-ow.s of stigmas . . G. eleganfi Grun. 

 [ — — — — — — — — one or two stigmas 2. 



Oostse about tl in 0,0 1 mm 6r. Mamilla Ehb. 



— — 12 — — 6r. herculeana Ehb. 



1. (j. elegans Giuin. (1880). — V. sublanceolate, tapering from the gibbous middle to the 

 l)i-oad rounded upper end, and to the narrower basis. L. 0,i2 to 0,15; B. 0,028 to 0,o3 mm. 

 Median line broad ; oblique). Axial area narrow; central area orbiculai", witli a circlet of stigmas. 

 Costcfi 10 in 0,0 1 mm., radiate in the ends. Puneta 22 in 0,oi mm. Longitudinal lines distinct, 

 median. — Gomphoncma elegans Grun. V. H. Syn. PI. XXV f. 19. 



Fresh water: Shasta Co. Cal. foss. (Cl. M. D. N:o 2(54), Pitt River, Oregon (Grove Coll.)! 



2. G. Mamilla Ehb. (18/)4). V. lanceolate, gradually tapering to the obtuse, narrow ends. 

 L. 0,09 to 0,15; B. 0,02 to 0,03 mm. Axial area narrow, linear. Central area small, rounded, 

 with one or two stigmas. Co.stse slightly radiate at the ends, 8 to 10 in 0,oi mm., alternating 

 with double rows of fine puneta, forming obliquely decussating rows, 16 to 20 in 0,oi mm. Longi- 

 tudinal lines marginal. - Gomphoncma Mam. Ehb. M. G. XXXVII: 2 f. 10. V. H. Syn. PI. XXIII 

 f. 1. Gomplioncma oregonicmn car. maxima Grun. V. H. Syn. PI. XXIII f. 8. 



Fresh water: Shasta Co. Calif., fossil! Pitt River, Oregon (Grove Coll.)! 



3. G. herculeanum Ehb. (184.5). — V. elavate, with broad and rounded or sul)truncate 

 upper ends. L. 0,ofi to 0,i ; B. 0,o2 to 0,022 mm. Axial area very narrow; central area small, 

 rounded, with one stigma. Costre .slightly radiate at the ends, about 12 in 0,oi mm., alternating 

 with double rows of puneta (about 22 in 0,oi mm.) forming obliquely decussating rows. Longi- 

 tudinal lines faint, sometimes obsolete, median. — Gomplinnema /lercid. Ehb. Ber. 1845 (according 

 to Chase). Grun. Casp. Sea Alg. p. U. V. H. Syn. PI. XXIII f. 2. 



Fresh water: New York! Lake Erie (Cl. M. D. N:o 40)! Winnipeg River, Manitoba 

 (irove Coll.)! 



K. Sv. Vet. Akad. Hand!, Bd 26. N:o 2, 10 



