174 Transactions of the Society. 



Aulosphaeridae (Haeckel), amongst the Kadiolaria, but its whorled 

 hexradial spines, and tlie excessive delicacy of the skeleton, are 

 suggestive of the derm of some sponge. Nevertheless, the figure 

 given by Haeckel of AuJo'sphsera elegantissima Haeck,, on plates x. 

 and xi. of ' Die Radiolarien,' decides the question. 



The second body with Radiolarian appearance in the continuous 

 skeleton, has a distinct hexactinellid brush-spicule in the sarcode 

 adhering to it, and the resemblance of the areolation to that of some 

 of the Dictyonine Hexactinellid sponges is perfect. Nevertheless, 

 there are doubts in my mind whether it ls one of the Spongida ; for 

 unless the oscule has been turned in and the sides cruslied down 

 and more or less obscured by sarcode, during the process of 

 mounting, there is not one at all. The brush-spicule and some 

 elongate ones are, however, very difficult to account for on the plea 

 of being accidentally adherent. 



I. The following are the characters of the Aulosplisera : — The 

 body is irregularly ovoid in shape and closed. It consigts of one lajer 

 of continuous spiculae, forming a network of hexagons, and the whole 

 of the included space is unoccupied by any skeletal structure. The 

 hexagons forming the meshes are equal in size, have a very regular 

 direction in longitudinal series parallel with the long axis of the body. 

 Each hexagon consists of six equal spiculae which meet centrally, and 

 of six other spiculas which join their eccentric ends and form the 

 outline. The spiculae are very slender, straight, equal in thickness, 

 cylindrical, and hollow ; and the interspaces are large and equal. 

 The geometrical arrangement is therefore exceedingly perfect ; and 

 as similar hexagons in contact at their outlines permit of their radii 

 and bases being confused, the eye notes that the spiculae of one 

 hexagon may be said to form parts of the neighbouring ones. No 

 swelling occurs at the junction of the spiculae, but wherever any 

 meet, there projects a spicule perpendicularly, and it is remark- 

 able in form. The body is thus hirsute with projecting spiculae, 

 and they are extremely slender, long, and are marked by nearly 

 equidistant whorls, from seven to nine in number, of four radiating, 

 minute, and slightly recurved spiculas. Either the projecting 

 whorled spicule ends with a whorl, or it is produced as a linear spine. 

 The length of one of these spiculae is nearly equal to that of one of 

 the skeletal spiculae, but they are much more slender than the 

 hollow skeletal parts. Where the base of the projecting spicule 

 meets the ends of the skeletal spiculae, these last are hollowed, as it 

 were, for its inception. Some of these remarkable spiculae are in 

 place in the specimen, others have been broken ofi", and many have 

 been injured or are rudimentary ; but there are many of the type 

 described. The largest are • 063 mm. in length. 



The length of the whole body is nearly 2 mm., its height 

 1 "5 mm., and the breadth of each hexagonal system is •125 mm. 



