COSMARIUM. 93 



A species originally found in Minnesota, by Miss Eloise 

 Butler, now turns up also in New Jersey, Splitrock Pond, and 

 more recently Mr. W. N. Hastings has been collecting fine 

 specimens near Rochester, Kew Hampshire. The specimen 

 represented, Plate XXII, 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. 



C. Beoomei, Thwaites. Plate XX, flg. 6-9. 



Usually as long as broad, sometimes slightly longer, 

 obtuse-quadrangular; sinus narrow linear ; semi-cell oblong- 

 quadrangular, twice as broad as long, angles, inferior and 

 superior, obtusely rounded, base plane, end broadly truncate 

 and often slightly retuse, or moderately convex; end and 

 side views evidence a distinct central inflation ; cytioderm 

 rough with pearly granules arranged in suberect lines. 



Diameter 30-45 yU. 



Appears to be entitled to the term "common." 



C. PsETJDOBEOOMBi, Wollc. Plate LXII, fig. 36, 37. 



This new species is in all its details of structure like the 

 preceding, but entirely devoid of a central inflation. 

 Diameter 30-45 yu. 



Wood Lake, northern New Jersey, furnished scores of 

 specimens of this species the past Summer, 1883. 



C. BiEETTJM, Breb. Plate XX, figs. 1. 2. 



Subquadrangular or polygonal ; a deep constriction forms 

 a narrow linear sinus ; semi-cells obtuse-quadrangular, with 

 subreniform base, and end broad, subplaue-convex, dilated ; 

 cytioderm rough with pearl-like granules arranged in con- 

 centric series ; end view shows a prominent central swelling. 

 Diameter 55-60 yu. 



Rather rare, singly among other Algce, but occasionally in 

 quantities. Had a cluster of Oedogonium. from a sluggish 

 stream near Closter, N. J., literally covered with specimens 

 of this species. 



Var. FXORIDENSE, WoUe. Plate XLVI, fig. 6. 



Diifers from the typical form in its somewhat larger size, 

 but principally in the retuse ends. 

 Diameter 70 jx. 



Frequent along the shores of lake at Kissimme, Florida. 



C. CAELATUM, Ealfs. Plate XXI, figs. 46, 47, 48. 



Suborbicular, deeply constricted, sinus narrow linear ; 

 semi -cells subsemicircular, diameter equal to twice the 



