1887.] NATURAL SCIENCES OF PHILADELPHIA. 275 



foraminal tubule shorter than that of either of the previ- 

 ous species, surrounded and terminated by one or two long 

 and broad, ribbon-like cirrous appendages-rZ. 

 Fig. VI. Carterius tenosperma. Section as before ; the short tu- 

 bule -a, divided into several long, slender cirrous appen- 

 dsiges-d. 



Plate VII. 



Fig. I. Sjoongilla lacudrls. From an Ice Lake, on the Sierra 

 Nevada Mts, alt. 7000 feet -.-a, skeleton spicule ; b,h,h 

 bent, cylindrical, acerate gemmule spicules ; c,c,g, spined 

 acerate "dermal" or flesh spicules. Received from Dr. 

 H. W. Harkness, through Miss. M. M. Greer. 



Fig. II. Spongilla lacustris. From Ridley Creek, near Media, 

 Pennsylvania :-a,, skeleton spicules; b,b,b, acerate gem- 

 mule spicules ; c,c,c, "dermal" acerates. 



Fig.|III. Spongilla lacustris. From English type, received from 

 H. J. Carter :-a,a,a, skeleton spicules ; b,b, etc. acerate 

 gemmule spicules ; c,e, dermal acerates. 



Fig. IV. Spongilla lacustris. From May's Landing, New Jersey: 

 -a,a,a, skeleton spicules ; b,b, long, spinous, acerate gem- 

 mule spicules ; c,c, small dermal acerates. 



Fig. V. Spongilla lacustris, var. lehighensis. From the Lehigh 

 River, at White Haven, Pennsylvania:-a,a, skeleton spic- 

 ules; b, b, b, strongly spinous gemmule spicules; c,c,c,c, 

 short dermal acerates. 



Fig. VI. Spongilla lacustris, var. montana. From Lake on Cats- 

 kill Mts., New York, alt. 2500 feet; representing skeleton 

 and gemmule spicules; no dermals have been drawn. 



Plate VIII. 



Fig. I. Spongilla fragilis. From type specimen "presented by 

 Dr. Jos. Leidy to the Academy of Natural Sciences, Phil- 

 adelphia: "-a,a,a,a, skeleton spicules ; b,b,b,b, spicules from 

 the "cellular parenchyma." 



Fig. II. Spongilla fragilis, var. minutissima. From Lake Hopat- 

 cong, New Jersey :-a,a, skeleton spicules ; b,b, spined forms 

 sometimes seen; c,c,c, long, irregular, spinous parenchymal 

 spicules. 



