158 



THE SPONGES. 



skeletal lamella may be regarded as the equivalent of a longitudinal fibre, 

 on which the radial outgrowths are so thick as to be continuous. 



In P. folium 0. Schm. from the Florida coast (0. Schmidt, 1870, p; 62), 

 the entire thickness of the lamella is occupied by the reticulum of longi- 

 tudinal fibres as in P. lamelligera. But the lamella is thin, about 1 mm. 

 thick in the piece examined (from a specimen in the Museum of Compara- 

 tive Zoology), and the spiculo-fibres are slender and not flattened. The 

 spiculation in Schmidt's species is very similar to that of P. ventilabrum. 



> 



1870. 

 1882. 



1887. 

 1889. 

 1894. 



Auletta 0. Schmidt. 



Auletta 0. Schmidt, 1870, p. 45. 

 Auletta Schm., Vosmacr, 1882, p. 41. 



Vosmaer, 1887, p- 341. 



Dendy, 1889, p. 92. 



Topsent, 1894 a, p. 25. 





cc 



cc 



cc 



cc 



cc 



cc 



Auletta dendrophora, sp. nov. 



Plate 19, Figs. 4, 5, 7 ; Plate 25, Fig;. 2. 



Diagnosis. Sponge arborescent, produced by the continued branching of an originally 

 simple cylindrical body. Terminal branches, "persons," 5 mm. in diameter and 15-20 mm. 

 high, with terminal oscula. Paragastric cavity cylindrical, about 1.5 mm. in diameter, 

 and continuous throughout the colony. Obliquely branching radial canals extend from 

 the paragastric cavity toward surface. Pores, irregularly scattered between the project- 

 ing tufts of spicules, open into subdermal chambers. Color, light yellowish brown. 



Spicules. 1. Strongyle, slightly curved once or oftener, commonly 400-600 /x x 18-20 f i. 

 2. Style, common size in longitudinal fibres, 600 /x x 22 /x ; common size in radial fibres, 

 360 fi x 18 p. 3. Style, 170 /x x 8 /x. Skeletal framework consists of longitudinal spiculo- 

 fibres with transverse connectives, and of radial fibres, which extend from the longitudinal 

 fibres to the surface, there ending in projecting tufts of spicules. 



W 



c 



The sponge, which may be regarded as a continually branching cylinder, 

 consists of a short vertical stalk, above which the branches spread outward 

 and upward, fusing with one another to a considerable extent over their 

 lateral faces. In the perfect specimen (Fig. 7, Plate 19), the stalk is 

 10 mm. high and 8 mm. thick, and was obviously attached by its somewhat 

 expanded and concave lower end. The total height of the specimen is 

 55 mm. and the greatest breadth 75 mm. From the apex of the stalk the 

 branching has not extended symmetrically in all directions. If a vertical 

 plane be passed through the stalk and the direction of greatest width, the 



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