2Y0 Report of the State Geologist. 



acter. In determining the latter there is a degree of uncertainty 

 necessarily dependent on viewing only one plane, which cuts an 

 object whose" members lie in three. The original arrangement of 

 the spicules has doubtless been lost, as they lie in great confusion, 

 but usually, at or near the outside of the section, a number of 

 spicules can be distinguished which may be referred with consid- 

 erable certainty to the dermal layer. These spicules are larger 

 than the other sponge elements, and appear to be pentacts, which 

 rather favors the conclusion that they were originally of a 

 dermal position and character. 



There is every reason to believe that the remaining spicules are 

 hexacts or tetracts, and that monacts also are present. As all 

 the spicules distinguishable in these sections are composed of 

 simple, straight rods, destitute of spines, I have placed in another 

 species the elaborate and spinose forms found free, and have 

 referred^ to Lysactinella Gebhardi the simple elements, whether 

 occurring free or as spicular casts. In section a few of the spic- 

 ules appear to have five arms in a single plane, with the possibility 

 of two others at right angles to them. This may be the case, or 

 it may be the result of the imperfect orientation of*the arms 

 geometrically. This is not uncommon and might permit a sec- 

 tion to cut portions of fiNQ hexactinellid arms. At all events, the 

 number of such abnormal instances is so small that it can not 

 affect the systematic position of the sponge. An outline, natu- 

 ral size, of a section taken near the center of the specimen is 

 given on Plate II, figure 3. It measures in width 23 mm. ; in 

 height 9 mm. 



Lysactinella pekelegans, sp. nov. 

 Plate I, figures 22-31; Plate II, figure 1. 



Body of the sponge not known. Spicules ornate, with various 

 arrangements of spines, thorns, etc. 



Horizon.— Both these species are found in the Shaly limestone 

 at the Indian Ladder, Albany county. New York. 



INCERTAE SEDIS. 



Ischadites, Murchison, 1839. 



IscHADiTEs Squamjfek, Hal], 1859. 

 Dictyocrinites, Conrad, 1841. Ann. Rep. Geol. Surv. New York, plate, fig. 22. 

 Dictyocrinites squamifer, Hall, 1859. Pal. New York, voL III, p. 135. 

 BeceptaciiUtes squamifer, Hall, 1883. Rep. State Geologist for 1882, expl. PI. 

 XXIII, figs. 1, 2. 



