g98 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



Genus HALISCEPTRUM. 

 Pennatulida? in which the leaves are devoid of spicules. 



HALISCEPTRUM CYSTIFERUM, new species. 



Plate LXXXVI, fig. 1. 



Colony attaining a height of 120 mm. Length of stem to rudi- 

 mentary leaves 65 mm. The terminal bulb takes the form of a 

 remarkable bladderlike expansion, oval to round in shape, an average 

 one measuring 9 mm. by 6 mm. The bladder is translucent, with 

 fine annular markings produced by muscle bands in its walls. Above 

 this bladderlike structure is another swelling of the stem, such as 

 usually found in this group, about 30 mm. long. 



The axis cylinder terminates at about the middle of this swelling, 

 and protrudes considerably above the distal pinnae in all of the 13 

 specimens secured. 



The ventral side of the stem has a distinct groove, and the bladder 

 has an internal, longitudinal membranous septum which divides the 

 stem cavity into two chambers, at least in its lower portion. 



The pinnae are very short, and so closely set that the polyps appear 

 at first sight to be attached to the stem direct. There are about 32 

 pairs, counting the rudimentary ones. The fully developed pinnae 

 are nearly crescent-shaped, the concavity embracing the stem. 



The polyps are 4 or 5 to each well-developed pinna, large in pro- 

 portion to size of pinnse, apparently not completely retractile, ovate 

 in vertical section. 



The margins are somewhat inflected and ornamented with 8 lobes. 

 Some of the calyces are much longer than others. 



Zooids do not seem to be present in this species. 



Spicules are also apparently absent, or they are so small and scat- 

 tered as to escape observation. 



Color. — In alcohol, light buffy brown. 



Type-specimen. — Cat. No. 25423, U.S.N. M., Albatross station 4541. 



Distribution. — Station 4514, Point Pinos light-house S. 39° E. 

 10.7 miles, 394-524 fathoms; Station 4541, Point Pinos light-house 

 S. 41° E. 9.3 miles, 609 fathoms. 



The distinction between pinna? and sessile polyps here seems diffi- 

 cult. The pinna? might be regarded as groups of adherent, sessile 

 polyps. In this case the species would have to go into another family, 

 probably the Yirgularida^, which illustrates the distance which has 

 yet to be traveled before we have a really natural classification of the 

 pennatulids. 



Family STYLATULID^. 



Colony long and slender, with small pinnules which are supported 

 beneath b}- a calcareous plate composed of fused radiating spicules. 



