1855.] 385 



July 17th, 1855. 

 Major Le Conte in the Chair. 



A letter was read from the Corresponding Secretary of the Califor- 

 nia Academy of Natural Sciences, transmitting the Proceedings of that 

 Society, vol. i. pp. 1 45. 



Dr. Leidy presented a paper intended for publication in the Proceed- 

 ings, entitled, " Descriptions of some new Marine Invertebrata, by 

 William Stimpson, Zoologist to the U. S. Surveying Expedition to the 

 North Pacific, Japan Seas, &c, under Commander C. Ringgold, U. S. N." 

 Communicated by the Smithsonian Institution. Referred to Dr. Leidy, 

 Dr. Bridges and Mr. Cassin. 



July 2ih. 

 Vice President Bridges in the Chair. 



Letters were read 



From the Trustees of the New York State Library, dated Albany, 

 20th July, 1855, acknowledging the receipt of last No. of the Proceed- 

 ings. 



From the Smithsonian Institution, dated Washington, March 26, 

 and June 16th, 1855, also acknowledging receipt of same, and of the 

 Journal, Part i. Vol. iii. 



From C. F. Hagedorn, Esq., Bavarian Consul, announcing the de- 

 cease of Dr. J. G. Fliigel, of Leipsic. 



Dr. J. Aitken Meigs read a paper intended for publication in the 

 Journal, entitled, " Relation of Atomic Heat to Crystalline Form." 

 Referred to Dr. Leidy, Dr. Bridges and Dr. Drysdale. 



July 31st. 



Vice President Bridges in the Chair. 



The Committee on Mr. Stimpson's paper, read 17th inst., reported in 

 favor of publication in the Proceedings. 



Descriptions of som. new Marine Invertebrata. By Wm. Stimpson, Zoologist to the 

 U. S. Surveying Expedition to North Pacific, Japan Seas, etc., under direction of 

 Commander C. Ringgold, U. S. N. 



(Communicated by the Smithsonian Institution.) 



ECHINODERMATA. 



1. Ophiothrix spongicola. Disk covered with short spines, except on the 

 large triangular plates at the bases of the arms ; the sides with scattered, mi- 

 nute spines; the interbrachial plates below subrhombic ia shape. Arms in 

 length seven times the diameter of the disk, broad near their origins but very 

 slender at their extremities ; lateral spines six in each row, the upper ones being 

 largest, subclavate, with rounded extremities, compressed and distantly serrated. 



PROCEED. ACAD. NAT. SCI. OF PHILADELPHIA. VOL. VII. NO. X. 30 



