EEPOET ON THE PENNATULIDA. 21 



Stalk cylindrical, tHin, with a moderately thick sarcosoma. Axis quadrangular, ^-ith 

 concave surfaces and rounded edges. 



The only specimen of this Umhellula brought home by the Challenger is evidently 

 young. Fig. 36 gives a clear idea of its appearance, so I mention only the following 

 details : — 



The length of the whole polypidom is 108 mm., and that of the rachis with the polyps 

 23 mm. The polyps, four in number, are situated on both sides of a short and small rachis 

 in such a manner that the rachis with the axis seems to enter the uppermost pol)-p, 

 whilst the others lie on its sides, two on the left and one on the right side. The needles 

 in the bodies of the polyps are disposed transversely, and measure 0-5 mm. in length and 

 0-030 to 0-041 mm. in breadth. Those of the tentacles are smaller, 0-27 and 0-21 mm. 

 placed longitudinally at the aboral side of their axes and pinnules, and transversely on 

 the oral face of the axes. All the needles are three-edged, and granulated only at their 

 ends. The calcareous bodies of the stem are short and broad, O'lO to O'lS mm. long, and 

 0-027 to 0-054 mm. wide oblong, shghtly constricted in the middle, flat, and covered 

 with strong prominent warts. 



Habitat.— Station 246, North Pacific Ocean, between San Francisco and Yeddo, 

 lat. 36° 10' N., long. 178° 0' E. Depth, 2050 fathoms. Bottom temperature, l°-3 C. 

 Grey ooze. July 2, 1875. 



6. Umhellula huxleyi, n. sp. (PL IX. fig. 37). 



Indistinctly bilateral in the fully-developed state. Calcareous corpuscles none, except 

 in the end-bulb of the stalk. Polyps forming a cluster at the end of the stalk, with 

 traces of a bilateral arrangement, small, brown. Stalk with a long enlargement below, 

 ending in a kind of bulb, and a large thickening at its upper end, where it appears 

 flattened and curved in such a manner that the axis lies at the convex side. Zooids 

 numerous on the whole stalk and between the bases of the polyps, but none on the 

 dorsal side of the rachis between the polyps, all provided with one single tentacle. 

 Axis indistinctly quadrangular. 



The Challenger brought home four specimens of this curious form, which being 

 difierent in size and age, gave me an insight into the development of the polypi- 

 ferous part. • 



Two younger specimens had four and five polyps. One of these may be named 

 the terminal pol}^^, as the axis ends in its body, and in one specimen reaches even 

 as far as the line of attachment of the tentacles. Of the other pol}TDS, two, which may 

 be termed the lateral polyps, are placed below and on the sides of the terminal pol}-p, and 

 the rest (one or two), which I call the dorsal polji^s, ou the dorsal side of the lateral 

 poljqos. 



Of the more developed specimens, one had seven more or less developed polyps, 



