158 PROCEEDINGS OF THE ACADEMY OF [1887. 



A furtlier purpose, and one that I hold much at heart, is the 

 desire to revive, among scientists and lovers of nature, an apprecia- 

 tion of the apparentl)' almost forgotten fact of the existence of sponges 

 in our fresh Avater; to show them that they are easily found and 

 collected; that they are dee25lr interesting as living subjects of study, 

 microscopic and otherwise ; and that, by simple processes, their typ- 

 ical parts may readily be prepared for classification and the 

 permanent preservation of their various singular forms. With this 

 end in view the situations and conditions in which the American 

 species were found, have been briefly described, suggesting the hope- 

 fulness of an exploration of similar localities in other neighborhoods. 



During the last six or seven years the leisure time of a very busy 

 life has been largely occupied in the collection and examination 

 of sponge material. In this labor of love I have been greatly aided 

 by the contributions and correspondence of friends, till then 

 unknown, in mdely separated districts, for whose thoughtful kindness 

 I now desire to express my indebtedness. It Avere idle to attempt to 

 name them all ; but to Professors Allen, Cope, Hunt, Leidy and 

 Heilprin of Philadelphia, to Dawson, Hyatt, Bumpus and Osborn 

 in other localities, I am particularly indebted. As active workers 

 in the same field and during nearly the same period, I am glad to 

 acknowledge my constant obligation to my friends Mr. Henry Mills, 

 of Buffalo, N. Y. and Mr. B. W. Thomas of Chicago, 111., whose 

 names Avill frequently be found throughout the following pages. 

 More recently my valued friend and correspondent Mr. A. H. Mac- 

 Kay, of Pictou, Nova Scotia, has been untiring in his efforts, very 

 successful in his local and New Foundland collections and most 

 generous in the contribution of his valuable material. I owe to my 

 friend Prof John A. Ryder of the University of Pennsylvania, what 

 has been of more value than any material, the most unfailing courtesy 

 and the best of advice, assistance and encouragement to persevere 

 in my work. From abroad I have been honored with the correspon- 

 dence and publications of Dr. W. Dybowski of NiankoAV, Russia, 

 Prof Marshall of Leipsig, Vejdovsky and Petr of Prague, Bohemia. 

 Prof. Vejdovsky has laid me under especial obligations by his repeated 

 gifts of Bohemian and other European sponges, besides his "Diagnosis 

 of the European Spongillidae" now published as a very valuable 

 contribution to this paper. I thank Dr. C. W. de Lannoy, late of 

 Chester, Pennsylvania, for the original drawings for plates V aud 

 VI the excellence of which will be conceded by all acquainted 

 with the subjects. 



