PORIFERA. II. 



41 



sorts of chelae, so that an identification with this species, is, for many reasons, excluded. Vanhoffen 

 has further overlooked the peculiar small chelae 1 ). 



Locality: The whole specimen has been taken by the Iugolf-Expedition at Holstensborg at 

 a depth of 30 fathoms, and the loose fragment has been taken off Cape Dalton, East-Greenland, depth 

 9 — n fathoms (the Amdrup-Expedition 1900). 



Gcogr. distr. Vanhoffen has the species from West-Greenland, Karajak-Fjord, and mentions 

 that it occurs as incrustations on worm tubes and Bryozoa. 



5. M. titubans O. Schmidt. 



PI. X, Fig. 3 a. — h. 



1870. Desmacidon titubans O. Schmidt, Grundzuge einer Spougienf. des atlant. Gebiet 55, Taf. V, 



Fig. 18 a — c. 

 1882. Desmacidon titubans Carter, Ann. Mag. Nat. Hist. Ser. 5, IX, 298, PI. XII, fig. 24 a— h. 



Form? The skeleton an irregular network consisting for the greater part of polyspicular fibres. 

 Spongin wanting. Spicula: Megasclera sty ii of two forms, larger ones o-jp — o-o'""'. smaller o/ics o-j2 — 

 0-40"""; microsclera of two forms . anisochela of a peculiar, wry form 0-024 — 0-032""", sigmafa o-oj 

 —0-14""". 



Of this species, so peculiar and characteristic by the form of its chelae, we have only very little 

 material, so that I can only to a slight degree supplement the description given by Schmidt 1. c. as 

 to the exterior and skeletal structure. With regard to the outer form Schmidt only says, unform- 

 licher, unregelmassiger Korper . The fragments in hand are also of a quite irregular form; the largest 

 one is irregularly bifurcate and somewhat flattened; its extent in length is 25™™, but it is probably 

 only a quite ruined fragment The colour (in spirit) is yellow to olive. I can say nothing of its sur- 

 face, pores, or oscula. 



The skeleton appears as a rather irregular network of mostly polyspicular fibres, and longi- 

 tudinal fibres seem especially to be found, while the other network is quite irregular. Upon the whole 

 the fibres are not strongly marked, and no spongin has been observed. Schmidt says that the small 

 form of styli are found as irregular bundles placed obliquely to the fibres; as far as I have been able 

 to see, however, the fact is not so. The small styli seem to me to occur near the surface and the 

 dermal membrane, and perhaps partly to be lying horizontally in the skin, partly to project as peni- 

 cillate bundles. 



Spicula: a. Megasclera; these are styli occurring in two different forms, also of different size. 

 The large styli are evenly curved, the curve being almost always found nearest to the head-end and 

 more or less pronounced; the other end tapers to a middle-long, sometimes rather long point. Their 

 length is 0-59 — erg" 11 ", and the thickness is between o-oi5 ram and o-oig" 1 ™. Finer developmental forms 

 are found, but in rather small numbers. The styli of the other form are smaller; they are straight or 

 almost straight, only rarely slightly curved. The head-end is quite slightly swollen, most frequently, 



l ) On the preparations of Vanhoffen determined as E. intermedia, which he has lent to me, a query is found by the name, 

 and on one of them is added, < ist nicht intermedia , so that Vanhoffen seems himself to have noticed the erroneous determination. 



The Ingolf-Expedilion. VI. 2. 6 





