196 [July, 1842. 



MEETING FOR BUSINESS, July 26, 1842. 



Vice President Morton in the Chair. 



After the reading of the Monthly Report of the Corrrespond- 

 ing Secretary, the following reports of committees were pre- 

 sented and adopted. 



The Committee on the following paper by Mr. Haldeman, 

 read July 5th, 1842, in favour of Publication in the Proceed- 

 ings. 



Description of two new species of Hydrachna and one of 

 Daphnia. By S. S. Haldeman. 



Hydr. nebulosa. Globular, mottled with brown ; a large central sub-rectangu- 

 lar spot back of the eyes, which are apparently double upon each side, red and 

 black ; an orange spot in the centre of the back ; legs very slender, first and 

 second pair thinner than the third and fourth ; palpi long, basal half cylindrical, 

 extremity tapering. More globular than my Unionicola oviformis, with a nearly 

 similar light Y shaped mark upon the back, and equalling this species in size. 

 Hab. A little pond on the Susquehanna, above Columbia. 



Hydr. coccinea. Subglobose, uniform bright scarlet, legs slender, covered with 

 short bristles ; palpi bristled, ante-penultimate articulation thickened. Length 4 

 millim. Hab. with the preceding. Differs from H. scabra, in being larger, and 

 in wanting the long bristles to the legs. The posterior legs are not " destitute of 

 cilia," wherein it differs from Limnochares cxtendens, Say. 



Daphnia reticulata. Ovate, margins imbricated, surface divided by fine lines 

 into minute rectangles; posterior half of the body with the dorsal and ventral por- 

 tion approaching each other by similar curves, which meet in a long, slender, 

 tapering caudal appendage. Closely resembles " Monocculus pulex." Jurine's 

 Hist, des Monocles, PI. 8. fig. 1. Length 1 millim. Hab. with the preceding. 



The Committee on Professor Locke's communication, read 

 July 5th, 1842, on the Fossil Cryptolithus tesselatus, re- 

 ported also in favour of publication in the Proceedings ; viz : 



So rarely do we meet with Fossils in such a state that we can unravel in any 

 degree the structure beyond the mere external form, that I sit down while the 

 subject is still new and exciting, to communicate to you what seems to me to be a 

 discovery in relation to the Cryptolithus tessellatus. This fossil is so seldom found 

 with anything more than the scuta and its ornamented margin, that some natu- 

 ralists have doubted the existence of an " abdomen" and " tail," similar to the cor- 

 responding parts of other trilobites. In examining a stratum of clay-marl which 



