36 



Hyalonema lieymonsi F. E, Sch. 

 Plate III, fig. 14-18. 



1895 Bynlonema heymonsi F. E. Sch. in Abh. Preuss. Ak. 1894 p. 29, Taf IV, fig. 14-18. 



The sponge described as Hyalonema heymonsi, of which there is but one 

 single small specimen in the " Investigator " collection, may possibly also be a 

 young Hyalonema indiciim. For the 'reason stated above, however, I prefer to 

 distinguish it for the present by a special designation and have named it heymonsi 

 after my friend and assistant, Professor Heymons, who greatly helped me in 

 this work by preparing the sections, etc., required. 



As is shown in the life-size figure of this sponge (fig. 14 on plate III) it is 

 rounded, spindle-shaped, 10 mm. long and 4 mm. broad. There is no oscule on 

 the upper end ; to the lower end a slender root-tuft, composed of not more than 

 10-20 basalia-spicules, is attached. The quadratic reticulation of the dermal 

 membrane is not yet clearly pronounced. 



The macroscleres are in their shape, size and arrangement, similar to those 

 of Hyalonema indicum and H. pirum. The microscleres show the following 

 peculiarities. The dermal pinules are of equal length (300-350 M ) but consider- 

 ably thinner, and the spines of the main ray are very short (pi. Ill, f. 18). 



The dermal macramphidiscs are similar in shape but shorter, less than 300 i" 

 long. Mesamphidiscs could not be found. Micramphidiscs are numerous and 

 resemble in shape and size those of Hyalonema indicum. 



The same applies to the micro-oxyhexactines. Plane, parenchymal micro- 

 oxytetractines are absent.. 



The only specimen of this sponge procured was captured in the Bay of 

 Bengal 9° 34' N., 85° 43' 15" E. in a depth of 3655 m.= 1997 fths. 



Hyalonema weltneri F. E. Sch. 

 Plate IV, fig. 15-24. 



1895 Hyaionema weltneri F. E. Sch. in Abli. Preuss. Ak., 1894, p. 30, Taf. V, fig. 15-24. 



Although the specimen on which this species is founded certainly represents 

 a young form, there can be no doubt about its being a good species, because its 

 dermal pinules are quite peculiar. I have named this sponge after my friend 

 and worthy collaborator in the field of spongiology Dr. Weltner, Gustos in the 

 Berlin Museum. 



The body is elongated, spindle-shaped, circular in transverse section, 16 mm. 

 long and in the middle 4 mm. thick (pi. IV, f. 15). The upper end is rounded 

 and destitute of an oscule ; from the lower end a root-tuft, composed of 15-20 



