REPORT ON THE HEXACTINELLIDA. 293 



are only sparsely present, somewliat slender in form, and thickly beset with long, closely 

 appressed, narrow barbs. 



Besides these, I find in the parenchyma, between the strands of the dictyonal frame- 

 work, isolated minute diseohexasters with six divergent, comparatively straight, terminal 

 rays of equal length, on each of the six short, slender principals, which exhibit small 

 knob-like terminal plates (PL LXXVII. fig. 9). 



The dermal skeleton exhibits medium-sized pentacts with much thickened rough and 

 rounded ends on the four gently incurved tangentials, a somewhat longer proximal ray 

 also with a rough rounded off" end, and lastly, a simple inconspicuous distal tubercle in 

 place of the atrophied sixth ray. Besides these hypodermalia which are united by their 

 tangential rays into a quadratic network, there are abundant, very characteristic — indeed 

 specifically distinctive — dermal scopulas in which the smooth stalk with a rough gradually 

 pointed proximal end is expanded distally in a conical fashion, and bears four, or rarely 

 five or six, cruciately disposed prongs. The thin stalks of these slightly divergent 

 prongs are usually slightly bent (PL LXXVII. fig. 5), and less frequently straight. 

 They are continued outwards into a smooth, spindle-shaped, thickened end, which 

 occasionally exhibits a somewhat sharply defined point and an internal sharp edge. 



The pentacts of the gastral skeleton resemble those of the dermal, but the scopulas 

 which occur beside them diff"er in some essential points from those in the dermal region. 

 The four to six thin prong-stalks, which are curved gently outwards, bear club- or pear- 

 shaped terminal thickenings which are thickly beset round about with short obliquely 

 disposed barbs. Only the outermost pole of the terminal prong-swelling remains free from 

 these minute teeth (PL LXXVII. figs. 6, 10). 



The soft tissue exhibits here, as in all species of Eurete, a continuous dermal and 

 gastral membrane with pores of very varied width, and a delicate subdermal and subgastral 

 trabecular framework, in which the usually simple and straight afferent and eS"erent 

 passages are seen as roundish canalicular spaces. The system of chambers forms a deeply, 

 but somewhat simply folded layer of small chambers of the ordinary type, and somewhat 

 sharply separated laterally from one another (PL LXXVII. fig. 2). 



2. Eurete schmidtii, n. sp. (PL LXXVIII. figs. 1-G). 



Among the numerous specimens of Eurete now at my command, there are three 

 which agree both in their microscopic appearance, and in the minute structure of the 

 skeletal parts. These belong to a new species which I have named Eurete schmidtii, 

 in honour of the illustrious spongiologist, Professor Oscar Schmidt of Strassburg. 

 Two of these are preserved in alcohol, and were brought home by the Challenger 

 Expedition, having been trawled in the neighbourhood of the Philippines at Station 201, 



