280 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 4 



medium length ; the third internode is athecate, longer than the first but 

 not so long as the second ; thereafter, the thecate and athecate internodes 

 follow in regular alternation. The internodes are all strongly septate, 

 with a septum flanking each node on each side. There is but 1 septum in 

 the first internode, and in the thecate internodes, there is a well marked 

 septum at the base of the hydrotheca. The supracalj^cine nematophores 

 are short ; there is 1 mesial nematophore on each internode with the excep- 

 tion of the first. There is a nematophore in the axil of the hydrocladial 

 process, and 1 near the distal end of that process; there are 2 cauline 

 nematophores for each portion that corresponds to an internode, on the 

 side opposite the hydrocladial process. 



Gonosome. — Not obsei-ved. 



Distribution. — Station 1419-41, 1 mile north of west end of Anacapa 

 Island, 45-47 fathoms. 



Plumularia irregularis, new species 

 Plate 39, Fig. 46 



Trophosome. — The colony, up to 20 mm, grows separately, not in 

 clusters. The stem is simple, nodes irregularly placed, usually with more 

 than 1 hydrocladium to an internode. The hydrocladia are all in the same 

 plane, but irregularly placed, all the way from strictly alternate to strictly 

 opposite. The hydrocladial process is not long but it has a nematophore in 

 the axil and 1 farther out. The first hydrocladial internode is thecate; 

 the second is athecate, and in most of the hydrocladia, thecate and 

 athecate inter-nodes alternate throughout ; not uncommonly there may be 

 2 athecate internodes of nearly the same length between 2 consecutive, 

 thecate internodes. There are a proximal, mesial nematophore, and 2 supra- 

 calycine nematophores on each thecate internode, and 1 mesial, on each 

 athecate internode. On the stem, there may be 2 nematophores between 2 

 adjacent hydrocladia on the one side, or there may be but one. The septa 

 in the hydrocladia are quite well marked. 



Gonosome. — Not observed. 



Distribution. — Station 1123-40, off San Nicolas Island, 28-31 fath- 

 oms. 



Remarks. — The species bears a general resemblance to P. setacea 

 (Ellis), but the hydrocladia are longer, and there are the several irregu- 

 larities mentioned. 



