44 



SCIENCE. 



Art. 35. Any member or fellow who shall pay the sum 

 of fifty dollars to the Association, at any one time, shall be- 

 come a Life Member, and as such shall be exempt from all 

 further assessments, and shall be entitled to the Proceed- 

 ings of the Association. All money thus received shall be 

 invested as a permanent fund, the income of which shall be 

 used only to assist in original research unless otherwise 

 directed by unanimous vote of the Standing Committee. 



Art. 36. All admission fees and assessments must be 

 paid to the Permanent Secretary, who shall give proper re- 

 ceipts for the same. 



Art. 27. All members and fellows must forward to the 

 Permanent Secretary, as early as possible, and when prac- 

 ticable before the convening of the Association, full titles 

 of all the papers which they propose to present during the 

 meeting, with a statement of the time that each will occups 

 in delivery, and also such abstracts of their contents as 

 will give a general idea of their nature ; and no title shall 

 be referred by the Standing Committee to the Sectional 

 Committee until an abstract of the paper or the paper itself 

 has been received. 



(Blank forms for giving the titles and abstracts of papers 

 will be furnished by the Permanent Secretary on applica- 

 tion. The Standing Committee particularly request, in 

 order to facilitate the arrangement of the programme, that 

 the titles and abstracts should be forwarded so as to reach 

 the Permanent Secretary before August ninth. At the 

 Saratoga meeting the Permanent Secretary was instructed 

 not to enter, on the list of papers to be presented, any titles 

 of papers until an abstract of the paper, or the paper itself, 

 was received.) 



Notice of errors in the printed list of Members of the 

 Association, of change of address, and information re- 

 specting the decease of Members, should be sent to the 

 Permanent Secretary in order that due notice may be 

 laken of the same in the next volume of " Proceedings." 

 It is particularly requested that the Permanent Secretary 

 be notified at once of any errors in the names and ad- 

 dresses that will be given in the list in the Saratoga 

 volume, as a revised edition of the list will be printed 

 for circulation at the Boston meeting. 



The Saratoga volume (vol. 28) will soon be distributed 

 by mail to every member who has paid the assessment 

 for the Saratoga meeting. 



The volumes of the Proceedings of the Association (28 

 in number) can be obtained from the Permanent Secretary, 

 at the price of $1.50 a volume ; or any member wishing 

 for ten or more volumes, in order to complete a set, may 

 obtain them at $1.00 a volume. The volumes may be had 

 bound in cloth for the extra price of fifty cents each, or in 

 one-half Turke) morocco for the extra price of $1.00 each. 

 Uniform cloth covers for the volumes will be furnished by 

 mail at thirty cents each, or by express or at the meetings 

 for twenty-five cents each. Copies of Volumes 2 and 26 

 will be received in exchange for other volumes or will be 

 purchased at $1.00 each. 



The Memoir on Fossil Butterflies, by Mr. S. H. Scudder, 

 published by the donation of Mrs. Elizabeth Thompson, 

 410, 1875, will be furnished at $2.00 a copy. The Transac- 

 tions of the Association of Geologists and Naturalists, 1 

 vol. 8vo, 1843, bound in cloth, can be obtained at $3.00 a 

 copy. 



It will save much lime and confusion at the meeting if 

 members will send their assessments in advance to the 

 Permanent Secretary, in return for which a Member's 

 ticket, bearing a receipt for the Boston meeting will be 

 forwarded. Members not intending to be present at 

 Boston, are particularly requested to send their assess- 

 ment in advance, and to those who specially request the 

 same a copy of the Boston Daily Programme will be 

 mailed. 



The address of the Permanent Secretary, F. W. 

 Putnam, Esq., will be Salem, Mass., until August \st ; 

 after that time, and until the meeting has adjourned, 

 his office will be at the Massachusetts Institute of 

 Technology, Boston, Mass. 



ON "LIMNOCOD1UM VICTORIA," A HYDROIU 

 MEDUSA OF FRESH WATER. 



A short time since I received from Mr. Sowerby, Secre- 

 tary of the Royal Botanical Society, a letter informing me of 

 the occurrence of certain Medusoid organizations in the 

 warm-water tank devoted to the cultivation of the Victoria 

 regia in the Gardens of the Society. The letter contained a 

 request that I should examine the animals with a view to 

 their determination ; Mr. Sowerby accompanied it with rough 

 sketches, and offered to place specimens at my disposal. 



The discovery of true freshwater Medusae was so startling 

 a fact that I lost no time in calling on Air. Sowerby, with 

 whom I visited the tank, and carried away such specimens 

 as were needed for examination. 



The water in the tank had then a temperature of 86° F., 

 and was literally swarming with little Medusas, the largest 

 of which measured nearly half an inch in transverse diame- 

 ter. They were very energetic in their movements, swim- 

 ming with the characteristic systole and diastole of their 

 umbrella, and apparently in the very conditions which con- 

 tribute most completely to their well being. 



As it now became evident that the Midusa belonged to a 

 generic form hitherto undescribed, I prepared for the Lin- 

 nean Society a paper containing the results of my examina- 

 tion, and assigning to the new Medusa the name of Lim- 

 nocodium victoiia (?J/uwr/, a pond, and kuSwv, a bell). This 

 was received and recorded by the secretaries on June 14, 

 and read at the next meeting, on the 17th.' 



The umbrella varies much in form with its slate of con- 

 traction, passing from a somewhat conical shape with de- 

 pressed summit through figures more or less hemispherical 

 to that of a shallow cup or even of a nearly flat disk. Its 

 outer surface is covered by an epithelium composed of 

 flattened hexagonal cells with distinct and bril- 

 liant nucleus. The manubrium is large ; it commences 

 with a quadrate base, and when extended projects beyond 

 the margin of the umbrella. The mouth is destitute of ten- 

 tacles, but is divided into four lips, which are everted and 

 plicated. The endoderm of the manubrium is thrown into 

 four strongly-marked longitudinal plicated ridges. 



The radial canals are four in number , they originate each 

 in an angle of the quadrate base of the manubrium, and 

 open distally into a wide circular canal. Each radial canal 

 is accompanied by longitudinal muscular fibres, which 

 spread out on each side at the junction of the radial with the 

 circular canal. 



The velum is of moderate width, and the extreme margin 

 of the umbrella is thickened and festooned, .and loaded 

 with brownish-yellow pigment cells. 



The attachment of the tentacles is peculiar. Instead of 

 being free continuations of the umbrella margin, they are 

 given off from the outer surface of the umbrella at points a 

 little above the margin. From each of these points, how- 

 ever, a ridge may be traced centrifugally as far as the thick- 

 ened umbrella margin ; this is caused by the proximate 

 portion of the tentacle being here adnate to the outer surface 

 of the umbrella, It holds exactly the position of the 

 " mantelspangen" or peronia, so well developed in the whole 

 of the Narcomedusae of Haeckel, and occurring also in some 

 genera of his Trachomedusiu Its structure, however, 

 differs from that of the true peronia, which are merely lines 

 of thread cells marking the path travelled over by the ten- 

 ia* li as tin- insertion of this moved in the course of meta- 

 morphosis from the margin of the umbrella to a point at 



1 Some facts in addition to those contained in my original paper are 

 included in the present communication. 



