raphanns subsequently received made it clear however that prostalia lateralia 

 are normally present in good specimens of this species both young and adult.* 

 The reason for uniting Pheronema and Poliopogon was thus invalidated and it 

 became necessary, as stated above, to re-establish Poliopogon Wyv. Thorns, as 

 a genus distinct from Pheronema. 



One of the Pheronema specimens was a small and badly preserved speci- 

 men which appeared to be distinguished from P. raphanus by the large size of 

 its prostalia marginalia and I established for it the species Pheronema circum- 

 palatmn F. E. Sch.t The examination of better preserved specimens of this 

 sponge subsequently received showed however that Pheronema circumpalatum 

 was merely a young P. raphanns-X 



Pheronema raphanus, F. E. Sch. 

 Plate I. 



1895 Pheronema raphanus F. E. Sch., in Abh. PrensB. Ak. 1894, pp. 8-13, Taf. I. 



„ Pheronema circumpalatumF. K. Sch., ibidem, pp. 13-17, Taf. II. 

 190O Pheronema raphanus F. E. Sch. in Abh. Preuss. Ak., 1900 pp. 3-7, Taf. I. 



The adult sponge is a hand in height and over. It has the shape of a 

 radish and its maximum transverse diameter, which is situated two finger- 

 breadths below the upper end, exceeds its height. The oscular margin is 

 nearly circular. The upper surface is occupied by a plain or slightly concave 

 sieve-plate. The sides bulge considerably in their upper part. Below, the 

 sponge is attenuated, inversely conical, and terminates in a rounded protuber- 

 ance two to three finger-breadths high. From this a root-tuft of spicules one 

 finger long and two to three fingers broad protrudes. This tuft is composed of 

 numerous spicule-bundles of the thickness of goose-quills. Above, the spicules 

 composing the bundles are firmly united and the bundles themselves perfectly 

 distinct. Below, the spicules diverge and the ends of the bundles unite to form 

 a continuous spicule-mass. 



The margin of the sieve-plate is alternately sharp and rounded ; its edge 

 appears as an undulating line slightly raised and sharpened at 5 (rarely 6 or 

 more) equidistant points. Marginalia arranged in a single row protrude from 

 it 2-3 cm. These marginaha are much larger and closer together on the sharp 

 protruding parts of the margin than in the rounded and depressed interstices 

 where they may be totally absent. The fringe they form accordingly appears 

 fully developed only on the elevated parts of the margin. The ratio of the 

 lengths of these well developed parts of the marginal fringe to the intervening 

 spaces differs in different specimens, but is fairly constant in one and the same 

 individual. The latter are usually longer than the former. 



* Abb. Preuss. Ak., 1900, p. 5. t Abb. Prenss. Ak. 1894, pp. 13-17. 



J Abli. Preuss. Ak. 1900, pp. 4-7. 



