1886.] NATURAL SCIENCES OP PHILADELPHIA. 39 



ON THE MINUTE STRUCTURE OF STROMATOPORA AND ITS ALLIES. 



BY DR. C. ROMINGER. 



I had only recently the opportunity of reading the joint essay 

 by Prof. Alleyne Nicholson and Dr. F. Mnrie on the structure 

 of Stromatopora, published in 1879, in the Journal of the Linnsean 

 Society of London. The communication treats for the most part 

 to the structure of the Stromatoporas found on the American 

 continent. 



As I had paid attention for a number of years to the study of 

 Stromatopora and had gathered extensive collections of them in 

 most of the localities from which the tj'pe specimens described 

 by these authors came, I had no difficult}" in identifying the forms 

 they had under consideration. While I was enabled in this way 

 to confirm the cori'ectness of some of their observations, I found 

 that in other instances they labored under erroneous conceptions, 

 parti}' because their material was insufficient, partly because they 

 did not recognize the things as they actually were. 



Of most of the forms described by them and of a number of 

 others I had over fifteen years ago worked out descriptions, 

 accompanied by sixteen plates of magnified photographic figures, 

 intending to have them published under the auspices of the 

 Smithsonian Institution. Those to whom the paper was referred 

 for examination, however, reported adversely, in view of the recent 

 publication of Baron v. Rosen's monograph on Stromatopora and 

 the undesirability, as they believed, of issuing so manj'' plates 

 with such a comparatively small amount of text. 



Messrs. Nicholson and Murie commence with an historical expo- 

 sition of the different opinions held by writers on the nature and 

 affinities of Stromatopora^ and after discussion of the arguments 

 for and against such opinions, they declare themselves with some 

 reserve in favor of the most popular of them, which was also held 

 by Goldfuss, the founder of the genus, that is to say, they think 

 the nearest relationship of Stromatopora is with the s})onges having 

 a calcareous skeleton. The authors think they have recognized 

 in Stromatopora systems of channels destined for the circulation 

 of water to and from the organism, analogous to those permeating 

 the mass of sponges ; but we shall see hereafter that these supposed 



