206 
THE VOYAGE OF H.M.S. CHALLENGEE. 
Spicules. — L Megasclere. 1. Oxea, fusiform, curved, T32 by 0*028 mm. 
II. Microscleres. 2. Oxyaster, very variable, centrum small, sometimes absent, 
actines conical, minutely spined, from one to twelve in number ; size variable, smaller as 
the actines are more numerous, maximum diameter 0‘06 mm. 
3. Sanidasters, exceedingly variable, the more regular and usually smaller forms 
presenting a straight axis subdivided into two or more spines at the end, and bearing two 
whorls of spines situated about one-third the length of the axis from each end ; the less 
regular present the same grotesque appearance as characterises the similar spicule in 
Stryphnus unguiculus; length 0*017 mm. 
Colour. — Tawny-brown. Size, 63 mm. in length by 25 mm. in height. 
Habitat. — Freemantle, Australia. 
Remarks. — The spicules of this species remind one of those of Stryphnus ; and in this 
genus there are species in which the trisene is both rare and small relatively to the oxea. 
If Asteropus is a reduced Stellettid it is to Stryphnus that we must look for its nearest 
alliance. In a type slide of the species kindly furnished me by Mr. Carter, I observed 
more than one oxea which presented a sudden flexure near the end, so as to present a 
form very similar to the reduced trisenes of some Tetillid species {Chrotella macellata). 
In such promonsenes the axial fibre stops short, and is slightly enlarged at the point of 
flexure, and then recommences as a distinct branch to supply what is practically a single 
cladus. 
Asteropus (?) annulatus (0. Schmidt). 
Stellettino'psis annulata, 0. Sch., Spong. Mexico, p. 75, pi. ix. fig. 6, 1880. 
Sponge. — Incrusting. 
Spicules. — I. Megasclere. 1. Oxea, long and slender. 
II. Microscleres. 2. Microxea (?*), short, stout. 3. Spiraster (?). 4. Oxyaster, cen- 
trum absent ; actines transversely ridged and tubercled. 
Habitat. — Gulf of Mexico, on Farrea. 
Remarks. — I have not seen specimens of this sponge. Its generic position is doubtful, 
If the spiraster so called should prove to be a sanidaster, it would naturally lead to the 
inclusion of the sponge in the genus to which it is here assigned. 
Genus Coppatias,^ n. gen. 
Epipolasidse in which but one form of aster, and that a euaster, is present. Canal 
system unknown. 
1 xoTTTroirlcii, branded with the letter koppa (i). The circle is fancifully supposed to represent the aster, the stroke 
the rhabdus, of this group of sponges. 
