1887.] NATURAL SCIENCES OP PHILADELPHIA. 229 



each side, cross each other iu a perplexing and beautiful manner. 

 (PL V. fig. vi.) 



Skeleton spicules slender, fusiform, gradually pointed, sparsely 

 and minutely microspined. 



Dermal spicules somewhat apocryphal. (While smooth, slender, 

 cylindrical forms that seem to be such, prove, in their further 

 development, to have been merely immature birotulates, jiertaining 

 to the gemmules, there are others, still more slender and acuminate, 

 that may be strictly dermal.) 



Birotulates of the gemmules very long and slender ; shaft cylin- 

 drical, whose length is five or six times the diameter of the suppor- 

 ted rotules ; abundantly spined, more particularly near the ends ; 

 spines long, cylindrical, rounded or recurved. Rotules composed of 

 3 to 6 short, recurved hooks with finely acuminate points. (PI. X, 

 fig. V, b.b.b.). 



Meas. Diameter of gemmules 0'013 inches. Skeleton spicules 

 0"01 by 0*0004 inches. Length of birotulate spicules 0*0025 inches. 

 Diameter of rotules 0-0004; of shaft 0-00015 inches. 



Hah. On fixed or floating timber in shallow water. 



Log. Crowe's Mill, Brandywine Creek; Ivy Mills, Chester Creek; 

 Fairraount Dam, Schuylkill River ; and League Island and Lam- 

 bertville, Delaware River, Pennsylvania. 



The tradition that associates the Brandywine Battle Ground with 

 the vision Lord Percy is said to have had of such a scene before 

 leaving England, as the spot where he should meet his death in bat- 

 tle, is so far justified by the fact that it is indeed one of the loveli- 

 est scenes in Pennsylvania. These undulating hills, crowned with 

 forest or Avaving with golden grain ; the emerald meadows lining 

 the broad stream on either side ; the smaller brooklets gathering in 

 the hollows and gurgling among the rocks, as they wind their way 

 down to the main stream, form a scene of peace and tranquility 

 which it is difficult to fill, in our own imaginations, with conflict 

 and bloodshed or cover with the "thunder clouds of war." 



It lay thus peacefully one summer day in 1881, when our wagons 

 drew up near the old fashioned grist and saw mills, then occupied 

 by Mr. Frank Crowe, about one mile above Chadd's Ford, made 

 famous on that Revolutionary occasion. Some of the party went 

 "a-fishing," but of course sponge hunting was the order of the day 

 with the writer. Drawing on high rubber boots, I waded into the 

 stream where the broad mill-race, a creek in itself though but a 



