PORIFERA. II. 



I6 5 



peculiar chelae are, on account of their smallness, only to be examined with difficulty. They consist 

 of a curved shaft, which has, at either end, a number of teeth or tooth-like processes. Their number 

 seems, at all events most frequently, to be about ten. The shaft is not smooth, but looks, as if it were 

 rather highly rugged. By sufficient high magnifying powers it is seen, however, that the shaft may 

 better be called lobate, as it has on either side a row of lobes, and these give to it its rugged appear- 

 ance. The lobes are placed in such a way, that in the middle of the shaft they are nearest to the 

 dorsal side, and when the chela is seen in a lateral position, the lobes in the middle are turned a 

 little backward; farther out on the shaft the lobes by degrees turn to the opposite side, and they 

 seem to pass evenly into the tooth-like processes of the ends, becoming at the same time longer. The 

 terminal parts of the shaft, from which the teeth issue, are a little expanded. The teeth may be some- 

 what varying in size, often the middle tooth or the middle teeth may be longest. The chela varies 

 somewhat in form, the shaft especially may be more or less curved. The described construction is 

 only to be distinguished under high magnifying powers. As mentioned, these chelae are very small, 

 their length is ca. crooS — o-oi5 mm , and the thickness is ca. oooi mm . — I have placed this peculiar spicule 

 to the chelae; I suppose that the rows of lobes of the shaft correspond to the alae, and then the 

 recurving part must correspond to a tooth, but nothing can otherwise be said as to the relations of 

 this spicule to the other chelae. 3. Sigmata are of the common form and more or less contort; their 

 length varies from 0-026 — o-05 mra , and the thickness about from o - ooi8 — o-oo30 ,nm . By far most frequently 

 the size is near to the larger limit. All the microscleres are frequent in the membranes through the 

 whole sponge and also present in large numbers in the dermal membrane. 



Remarks: As I have examined Fristedt's type specimen, the identification is sure. Fristedt 

 has not seen the construction of the small chela, which he therefore mentions as the small sigma, and 

 so he gets of microscleres one chela and two forms of sigmata, while in reality there are two forms 

 of chelae and only one form of sigmata. It is easily understood, on account of the smallness of this 

 chela, that he has not interpreted it correctly. His name indistincta shows that he has found 

 nothing characteristic in the species; but now this name is rather unhappy, as the species, on account 

 of the small chela, is especially distinct. When he says of the dermal spicules: «They are often curved*, 

 this expression is quite correct, as in his type specimen these spicules especially frequently occur as 

 curved; on the other hand, the figure of this spicule is quite a mistake with regard to one end. 

 Fristedt gives the length of the styli to 035 mm ; his type specimen belongs to those where the 

 smooth styli are predominant, and the styli are also, in conformity to what has been said above, com- 

 paratively short; I have measured them, however, of lengths of up to o - 4i7 mm . 



Locality: Station 34, the Davis Strait, 65 17' Lat. N., 54 17' Long. W., depth 55 fathoms; the 

 Davis Strait, 65 22' Lat. N., 54 02' Long. W., depth 60 fathoms (Wandel); the Davis Strait, depth 100 

 fathoms (Th. Holm); Hekla Harbour, depth 5 — 12 fathoms (the East-Greenland Expedition 1891 — 92). 

 About ten specimens or fragments in all. 



Geogr. distr. Fristedt has the species in one specimen from Spitzbergen, depth 60 fathoms. 

 The species seems to be a native of more shallow water, as it is only known from depths of 5 — 100 

 fathoms. 



