j6o The West American Scientist. 



That the debris are old is sure enough, the thick accumulation 

 of layers shows it plainly, but how long they have been abandoned 

 it is impossible to ascertain. The remains of cooking utensils 

 blackened by fire, and the ashes show only, that the tribes who 

 formed the Kitchen Middens lived under the shelter of tents, and 

 practised hunting and fishing, eating their spoils on the spot, just 

 like the other hunters of the stone age. 



M. Lopaiecki. 



FRESH- WATER SPONGES FROM MEXICO ^ 

 Meyenia plumosa, Carter, var. Palmeri, n. v. 



Sponge (as seen in a dry state; dark brown, massive, attached 

 to and surrounding the dependent branches of small trees, whose 

 stems are flooded by the spring freshets. Texture very loose, 

 and when dry so brittle that the dermal surface cannot be satis- 

 factorily examined; (The impression conveyed by the interior 

 appearance of this sponge is that it is made up of an infinite num- 

 ber of radiating confluent branches.) 



Gemmulae large, numerous througout the deeper portions of 

 the sponge; subspherical or ovoid, surrounded by long birotulates 

 imbedded in a granular crust. 



Skeleton spicules straight or slightly curved, mainly cylindri- 

 cal but gradually sharp-pointed, sparceiy microspined. 



Dermal spicules irregularly stellate as in the typical species, 

 but in the specimens examined much fewer in number. They 

 vary from simply acerates with one or more long divergent 

 branches to beautiful radiate spherical bodies whose rays are 

 nearly equal, spined, and capitate by reason of recurved spines at 

 their extremities. Another form of spicule, probably also dermal, 

 of which several are seen upon nearly every slide prepared for 

 microscopic examination, is very difficult of description. It may 

 be said to be composed of an irregular series of smooth curved 

 rays arising Irom a nearly common center, and is somewhat sug- 

 gestive of a hedgehog or Scotch terrier. 



Birotulate spicules pertaining to the gemmulae, in length about 

 three times the diameter of the supported rotules; shafts cylindri- 

 cal, plentifully spined: spines long, conical. Outer surface of 

 rotules convex, margin lacinulates; ends of incomplete rays 

 obtuse, recurved. Sponge masses subspherical, reaching five or 

 six in diameter. 



This sponge, collected by Dr. Edward Palmer along the banks 

 of the Colorado River, near l.erdo, Sonera, in Northwestern 

 Mexico, about 59 miles SSW. from Fort Yuma, California, is a 

 valuable addition to the sponge fauna of this continent, and inter- 

 esting from the fact that the typical species, M. plumosa of Carter, 

 has heretofore only been found in his original locality, the rock 

 water-tanks of Bombay, East Indies. That it should skip a whole 



* From Proc, U. S. Nat. 2 Miss., 1883, page 587 



