MAR 3 0 1907 
The Ohio ih^aturalist, 
PUBLISHED BY 
The Biological Club of ihe Ohio State University. 
Volume VII. MARCH. 1907. No. 5. 
TABLE OF CONTENTS 
Griggs— Cymathere, a Kelp from the Western Coast. 89 
Cook—T he Embryology of Sagittaria lancifolia L. 97 
Burgess— Experiments to Test the Diffusion of Hydrocyanic Acid Gas in E'umigating 
Houses. . 101 
McCamrbell—T he Public Drinking Cup. 105 
Stkrki—F ossil Land and Fresh Water Mollusca ColleC.ed in Defiance County, 0. 110 
Ortega— Key to Ohio Locusts in Winter Condition. 113 
Frank —Meetings of the Biological Club . 114 
CYMATHERE, A KELP FROM THE WESTERN COAST.* 
Robert F. Griggs. 
Cymathere is a genus of the Laminariaceae established by 
J. G. Agardh '67 to receive the older Laminaria triplicata of 
Postels and Ruprecht ’40. Though De Toni ’95 includes in it 
Laminaria crassifolia which has a branching holdfast, the genus 
is monotypic. Its sole species, Cymathere triplicata, is confined 
to the northern portion of the Pacific Ocean. It grows abundant¬ 
ly at the Minnesota Seaside Station on Vancouver’s Island where 
the plants herein described were collected. 
In its habitat Cymathere is the antithesis of such kelps as 
Postelsia and Lessoniopsis. Far from seeking the buffets of 
the surf, it retires into secluded nooks where the surge of the 
waves is no more than a gentle swishing to and fro. It does not 
succeed well except in situations which are never uncovered bv 
the tides. On this account the juvenile forms are difficult to 
obtain by the more usual methods of collecting. Those gathered 
by the writer w T ere secured by picking out of a pothole, in which 
the adult plants were flourishing, a number of stones as large as 
could be lifted easily. Search of these with a hand lens at leisure 
in the laboratory disclosed plants of all ages, down to the smallest 
obtained. 
At its maximum size the narrow oblong lamina of Cvmathere 
may reach a length of 4 meters and a breadth of 22 cm. No 
single specimen was seen, however, in which both these extreme 
dimensions were present. Most of the plants are quite narrow, 
only about half as wide as the broadest, which are very short 
with plicae very much broadened and less prominent than in 
narrower individuals. The base is cunate or rounded, narrower 
in young specimens and broadening afterwards as Yendo ’03 
has shown to be the case in Hirome undarioides. At the tip 
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* Contributions from the Botanical Laboratory of the Ohio State University, XXIX. 
