124 
FARREA OCCA SCUTELLA. 
Sometimes a continuation of the shaft extends beyond it, forming an apical, 
distally rounded, smooth protuberance, 6-7 p long and 4.5-6 p thick (Plate 27 , 
figs. 9, 10, 15). 
The rare clavules with short teeth (Plate 27 , fig. 12 ) are, apart from their 
teeth, similar to but smaller than the large-toothed ones above described. Their 
teeth are very short, hardly at all recurved, and the verticils formed by them 
only 18 p in diameter. Whether these clavules are young forms of the large- 
toothed ones, or a distinct kind of spicule, I cannot say. 
Their spiculation assigns these sponges to Farrea. Their shape, however, 
does not accord with F. E. Schulze’s diagnosis 1 of the Euretidae to which Farrea 
belongs, for in this diagnosis it is stated that these sponges are tubular. E. 
Topsent 2 , who has studied a sponge very similar to the one described above, says, 
concerning this part of Schulze’s diagnosis, “II ne faut evidemment pas prendre 
ce caractere trop a la lettre” and places these sponges of his, in spite of their 
non-tubular shape, in Farrea. I also am disinclined to attach any great system- 
atic importance to that difference of shape and therefore also place the sponges 
above described in Farrea. 
Of all the known species Farrea occa Bowerbank is obviously most closely 
related to them. A great many specimens, by no means identical in structure 
and appearance, have been assigned by various authors to this species, and for 
some of them distinct varieties and subspecies have been established by Topsent 
and Wilson. Although it seems to me very doubtful whether all the sponges 
assigned to Farrea occa are really specifically identical and belong to this spe- 
cies, and although I think that the forms described as varieties and subspecies 
of it might very well be considered as distinct species, I provisionally accept 
this arrangement, because it would lead much too far to reinvestigate all these 
sponges, and if we accept this arrangement, we must assign to this species so 
wide a range of variation that the sponges described above find a place in it. 
Among the sponges described as Farrea occa, those for which Topsent 3 estab- 
lished the variety F. o. var. foliascens are obviously most closely allied to F. o. 
var. scutella. From these they differ by the abundance of clavules, the scarcity 
and size (or absence, vide supra ) of the uncinates, and the larger dimensions of 
the superficial pentactines. Although these differences are not very great, 
they are, in my opinion, quite sufficient for varietal distinction particularly 
1 F. E. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4 , p. 177. 
2 E. Topsent. Farrea occa (Bowerbank) var. foliascens n. var. Bull. Mus. oceanogr. Monaco, 
1906, no. 83, p. 4. 
3 E. Topsent. Loc. cit., 1906, p. 1. 
