BY R. VON LEKDENPELD, PH.D. 1121 



Skeleton : The main skeleton is formed out of larger and 

 smaller, slender triradiate spicules. The large Triradiates are 

 mostly sagittal. The rays of which are slender, conic, mostly 

 straight, or slightly bent, 0"6 — 0" 9mm., rarely 1 — 12 mm., long 

 and only 003— 0-05 mm., rarely 0-06 — 0*08 mm., thick. The 

 smaller triradiate spicules, which are more numerous than the 

 large one, are irregularly scattered, and fill up the space between 

 the former, they are mostly sagittal or irregular. Their rays are 

 sometimes straight, or more or less, often strongly bent, on an 

 average of 0-2 — 0-3 mm. in length, and 001 — 0*02 mm. in thick- 

 ness. Triradiate spicules very variable. 



The Gastral surface and the inner surface of the larger wall 

 canals is clothed by a dense layer of middle-sized sagittal quad- 

 riradiate spicules. These are regular, parallel disposed, the basal 

 ray is bent aboral downwards, or in the canals, outwards, if 

 straight 025 — 0-35 mm. long. Both the lateral rays are slightly 

 curved, and a little shorter, only 0-15 — 0-3 mm. long. The angles 

 vary greatly, once nearly equal, once strongly differentiated. The 

 unpaired angle increases from 120°, L50'', and to 160'^, ISO'' in 

 the proboscis. 



Accordingly the paired angles decrease from 120° to 105° and 

 to 90°. Round the mouth there are only rectangular quadri- 

 radiate spicules. The apical ray varies greatly, mostly very 

 short, only 05 — 0-ld mm. long, slightly bent to the oral side. 

 All rays are at the base 0*01 — 0*02 mm. thick. 



Locality • Atlantic Ocean, Norman's Islands ; Guernsey, 

 Norman ; Coast of Mexico ; Mogados, Haeckel ; Cape of Good 

 Hope,Wilhelm Bleek ; Indian Ocean, Bass Straits, Wendt. 



37. SPECIES. LEUCALTIS BATHYBIA Haeckel (1). 

 grant: A ARABIC A. Miklouho (2). 

 LEUCALTIS BATHYBIA var. AUSTRALIS. Ridley (3). 

 Solitary Sponge, of a cylindrical or ovate rather irregular shape. 

 The specimen of Haeckel measured 8 to 16 mm., in length 4 to 6 



(1.) E. Haer'kd. Die Kalkschwiimme. Eine Monographie. Band II., 

 Seite 156, pi. XXVIII. , figs. 2a-2e. 



(2.) N. M. Maday. Manuscript. 



(3.) Stuart 0. Ridley. Report on the Sponges. Report on the Zoological 

 Collections made in the Indian and Pacific Ocean, during the Voyage of 

 H.M.S. Alert, 1S81-1882. British Museum Catalogue, 1884. 



