CALOCYLINDRUS. 33 



obtusely rounded ; sides somewhat convex ; in vertical view 

 broadly elliptic, apices somewhat produced 5 in lateral view 

 ovate. Membrane densely but distinctly punctate. Zy go- 

 spore globose aculeate, aculei broad at base, apices 2-3 furcate. 

 Diameter 25-26 j^ ; length 36 p. 



Tewksbury, Mass. Have given the figure of the type. 

 The form is closely related to C. pseudopyramidatum (Des. 

 U. S. p. 69); but the constriction is not so deep, the ends not 

 truncate, and in vertical view not distinctly elliptic. 



C. OCTOGONUM, Delp. var. CONSTRICTUM, Lagh. Plate LX, figs. 



34, 35. 



Cells in front view oblong- tetragonal deeply constricted ; 

 semi-cells trapezoidal ; in vertical view elliptic with middle 

 somewhat inflated; isthmus one-third of diameter of cell. 

 Membrane smooth. Var. constrictmn is more deeply con- 

 stricted, sinus wider, and semi -cell in vertical view not 

 inflated. 



Tewksbury, Massachusetts. From these specimens the 

 significance of the name is not evident. Instead of three 

 crenulations or angles on each side of a semi-cell, Delponte 

 describes "sometimes four," or eight to the semi-cell. Has 

 some resemblance to C. Braunii, Reinsch, but is not so 

 regular. 



C. SUBCRUCIFORME, Lagh. Plate LX, figs. 12-14. 



Small, somewhat circular, the constriction introrsely and 

 extrorsely anipliated ; semi-cells reniform, the end rounded, 

 not crenulate; angles rounded verrucose with margins 

 denticulate ; a central inflation granulate ; in vertical view 

 subcruciform, angles granulate ; in lateral view ovate- 

 circular. Membrane punctate. 



Diameter of cell 32 // ; length 36 ^ ; thickness 25 //. 







Reminds one of C. ornatum, Focke, and also of C. subreni- 

 forme, Nord. 



Tewksbury, Massachusetts. 



C. ELOISIANUM, Wolle. V. Des. U. S. p. 85. 



A species hitherto found only in Minnesota, now turns up 

 also in New Jersey, Splitrock Pond, and more recently, 

 (October, 1886,) Mr. W. ST. Hastings has been collecting fine 

 specimens near Rochester, New Hampshire. The specimen 

 represented, Des. U. S., Plate XIX, is an old form and caused 

 too many teeth to be illustrated. A single series on the 

 periphery of a semi-cell does not exceed 23-25. 



