566 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxxiv. 



Family PROTOCAULIDiE KoUiker. 



Polyps on both sides of rachis in a single series, or in indistinct 

 rows. Polyps small and without calyces. 



Genus PROTOCAULON KoUiker. 

 Polyps alternate, sessile. Spicules absent. 



PROTOCAULON MOLLE KoUiker. 



Protocaulon molle Kolliker Report on the Peimatulida dredged by H. M. S. 

 Challenger during^ the years 1873-1876, 1880, p. 26. 



A small specimen in poor condition answers well to the description 

 and figure of this species given in the original description. 



Distribution. — West coast of Hawaii : Station 4036, 692 fathoms 

 (Cat. No. 22543, U.S.N.M.). The type specimen was secured by the 

 Challenger northeast of New Zealand at a depth of 700 fathoms. 



Family PROTOPTILID^ Kolliker. 



Eachis long and slender, bearing sessile polyps in a single series of 

 indistinct rows on opposite sides. Calyces present. 



Genus PROTOPTILUM Kolliker. 



Zooids growing all around the rachis, leaving only the median ven- 

 tral line uncovered. 



PROTOPTILUM WRIGHTI, new species. 

 Plate XLII, fig. 7. 



Length of colony 65 mm. ; of stem to rudimentary polyps 21 mm. 

 Stem rather slender, without appreciable bulb, but hooked at proxi- 

 mal end, and with a slight SAvelling above the hook. Rachis larger, 

 increasing in size to the distal end. 



Polyps usually in two rows, one on each side, but with an occasional 

 one placed on the stem more toward the central line than the others. 

 In general the polyps are alternately disposed, placed rather on the 

 dorsal than the ventral side. They differ greatly in size, the smaller 

 (younger?) ones being nearer the mid-dorsal line than the others, 

 thus giving in places an appearance of an arrangement in rows of 

 two. There are many rudimentary polyps on the lower part of the 

 rachis. Calyces almost entirely immersed, their inner margins being 

 not at all exscrted; margins without distinct teeth, although the 

 needle-like spicules sometimes give an appearance of serration. 



