124 FARREA OCCA SCUTELLA. 



Sometimes a continuation of the shaft extends beyond it, forming an apical, 

 distally rounded, smooth protuberance, 6-7 m long and 4.5-6 n 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 M in diameter. Whether these clavules are young forms of the large- 

 toothed ones, or a distinct Idnd of spicule, I cannot say. 



Their spiculation assigns these sponges to Farrea. Their shape, however, 

 does not accord with F. E. Schulze's diagnosis ^ of the Euretidae to which Farrea 

 belongs, for in this diagnosis it is stated that these sponges are tubular. E. 

 Topsent ^, 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 '* estab- 

 lished the variety F. o. var. foliascens are obviously most closely allied to F. o. 

 var. scuteUa. 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 



' F. E. Schulze. Hexactinellida. Ergeb. Deutsch. tiefsee-exped., 1904, 4, p. 177. 

 ^ E. Topsent. Farrea occa (Bowerbank) var. foliascens n. var. Bull. Mus. oci'anogr. Monaco, 

 1906, no. 83, p. 4. 



= E. Topsent. hoc. cit., 1906, p. 1. 



