HOLASCELLA ANCORATA. 43 



chord, 20-23 m long and strongly curved in an S-shaped manner. Their basal 

 part is directed outwards and slightly backwards, their central part upwards 

 and slightly outwards, and their distal part again outwards and slightly back- 

 wards. They are exceedingly thin at the base, but thicken distally and attain, 

 a short distance from the end, a maximum transverse diameter of about 1.3 ft. 

 The end-rays are smooth on the inner side, that is the side turned towards the 

 continuation of the main-ray. On the opposite, outer side their thicker distal 

 part bears fairly large spines. 



As far as the fragmentary condition of the specimen allows one to judge, the 

 only species more closely allied to it is the specimen referred to by F. E. Schulze ' 

 as Holascus sp. and those described in this paper as Holascella taraxacum and 

 H. euonyx. It is very clearly distinguished from Holascus sp. Schulze and 

 Holascella taraxacum by the terminal spines of its discomicroscleres. In the 

 sponges described above these are long, slender, strongly recurved, and isolated 

 quite down to the base. In Holascella taraxacum they are certainly, and, to judge 

 by the figures, in Holascus sp. Schulze most probably, short, divergent, and 

 basally joined to form terminal tyles (' ' end-discs ") . From the former H. ancorata 

 also differs by the principals, which are in the sponge above described chiefly 

 tri- and tetractines, in H. taraxacum chiefly hexactines; by the discomicroscleres, 

 which have few end-rays in the former and very numerous end-rays in the latter; 

 and by the floricomes which are present in the former and appear to be absent 

 in the latter. There can, therefore, be no doubt that H. ancorata is specifically 

 distinct from H. taraxacum. Whether it is also distinct from Holascus sp. 

 Schulze, of which no adequate description exists, is not so easy to say, the 

 figures of this sponge given make it highly probable, however, that it belongs 

 to a different species. 



It appears to be more closely related to these species than to the sponge 

 here described as Holascella euonyx. From this it differs by the superficial 

 hexactines, the distal rays of which are much thicker and more club-shaped in 

 H. ancorata than in H. euonyx; by the discohexactines and hemidiscohexasters, 

 the rays (end-rays) of which are more spiny and bear much smaller terminal 

 anchor-teeth in the former than in the latter; by the onychhexactines and hemi- 

 onychhexasters, which have much shorter terminal spines in the former than in 

 the latter, and by the presence of floricomes in the former and their absence in 

 the latter. 



1 F. E. Schulze. Kept. Voy^ ChaUenger, 1887, 21, p. 86, 87, pi, 15, figs. 14-23. 



