1887.] NATURAL SCIENCES OF PHILADELPHIA. 263 



peiidages), whose bottom is pierced by the upright tubular part in 

 the usual way ; which "form" appears to prevail generally in the 

 statoblasts of this variety." 



2) Carterius tubisperma, Mills. Proc Acad. Nat. Sci. June 1881, p. 150. (PI. 

 VI, fig. iii.) 



Spongilla Mills. Am. Jour. Micros. June 1880, p. 132. 



Sponge brown or green, massive, loose textured ; surface wave- 

 like. 



Gemmulse numerous, spherical, relatively large; crust charged 

 with birotulate spicules. Foraminal apertures prolonged into slen- 

 der, cylindrical tubes, whose greatest length is about equal to the 

 diameter of the gemmule, abruptly flaring at their terminations into 

 several short, inconsequent tendrils of less or greater length. (PI. 

 VI, fig. iii, a.) 



Skeleton spicules rather slender, fi\sciculate, subfusiform, gradual- 

 ly pointed, sparsely spiniferous ; spines small, rounded. (PI. XII, 

 fig. vi, a.a.) 



Dermal spicules long, slender, acerates; generally straight, en- 

 tirely spined ; spines near the middle of the spicules long, cylindri- 

 cal ; terminations rounded. (Ibid, e.e.) 



Gemmule birotulates abundant, irregular in length, (suggesting 

 the genus Hetromeyenia); shafts cylindrical, sometimes with one or 

 more-spines ; outer surface of rotules arched ; rays numerous, long ; 

 terminations incurved (ibid, b.b.b.c.) 



Meas. Skeleton spicules 0-0099 by 0-00025 inches. Dermal 

 spicules 0-0038 inches long. Birotulates 0*0019 by 0*00015 inches. 

 Diameter of disk 0-0008 inches. 



Hah. On timbers etc. 



Loe. Niagara River, New York ; Cochituate Reservoir, Boston, 

 Mass. etc. 



The original description by Mr. Mills of his species, given as 

 above in June 1880, without specific name is as follows : — 



"Sponge low, branching (?) green, growing on the upper surface 

 of stones in not very deep water. Skeleton spiculse fusiform-acerate, 

 slightly arcuate, moderately stout, spined ; spines small, sparsely 

 distributed; length O'Ol to 0*012 inches, apices naked. These 

 are mixed with a great many fine delicate spicula (dermals) densely 

 spined to the end ; length 0-009 inches, scattered in groups on each 

 slide of mounted specimens. Ovaria globose; diameter 0*02 inches. 

 Foramen tubed ; tube terminating with five (?) finger-like processes 



