REPORT ON THE HEXACTINELLIDA. 355 



They are, however, in part very well preserved iii alcohol, so one cau learn someLhing of 

 the structure of the soft parts. The two specimens represented in natural size on 

 PI. cm. figs. 1 and 2 (of which fig. 1 represents two individuals united into one) 

 were obtained along with some fragments of other specimens, on blue mud ground, in the 

 vicinity of Little Ki Island (Station 192, lat. 5° 49' 15" S., long. 132° 14' 15" E.) in 

 140 fathoms. A somewhat larger cup was procured in the neighbourhood of Timor 

 (Station 194, lat. 4° 34' 0" S., long. 129° 57' 30" E.) on volcanic mud, at a depth of 

 200 fathoms ; and a small dried specimen, only about 1 cm. in height, from St. Thomas, 

 West Indies (Station 24, lat. 18° 38' 30" N., long. 65° 5' 30" W.) on Pteropod ooze in 

 390 fathoms. All these specimens have the form of a thick-walled cup which expands 

 upwards from a narrow basal plate. 



The lateral wall consists of a plate from 1 to 3 mm. thick, which is simply folded and 

 drawn out into radial open tubes. While in the small dried specimen from Station 24 

 these radial excurrent tubes of the gastral cavity are only 3 mm. broad, and are 

 almost all isolated towards the exterior, in the larger specimens from Stations 192 and 

 194, they have a tolerable breadth (as much as 5 mm. or more), and are fused to one 

 another laterally, so that they project externally in meandering lines or interwoven reticu- 

 late plates (PI. cm. figs. 1, 2). The free upper margin of the entire cup exhibits a sinuous 

 external curvature. This is also true of the regular funnel-shaped large specimen (10 cm. 

 broad, and 7 cm. high) figured by Gray (loc. cit.). The figure suggests that the radial 

 tubes have originated through closure of the parietal folds by growth of the entire body. 

 One may regard the entire upper aperture of the cup or funnel as the chief osculum, 

 and the lateral orifices of the tubes as secondary or incidental oscula. At all events the 

 water stream passes through the coherent plate in such a manner that it enters from the 

 outside into the depressions, furrows, &c., between the radial tubes, permeates the 

 continuous plate, and then reaches the lumen of the tubes which open out laterally, or 

 the central space which is in open communication with these, and thus reaches the 

 exterior, whether it be through the outer openings of the radial tubes, or through the 

 large terminal aperture of the central (gastral) cavity. 



The finer structure of the body is best studied in sections at right angles to the 

 wall plate ; one of these I have combined diagrammatically on PI. CIII. fig. 3 from 

 numerous preparations. 



The dictyoual framework consists of moderately strong beams. These are beset with 

 numerous small conical hooks, disposed in great part in regular cross rows. The beams are 

 united with tolerable regularity, and form for the most part distinctly square, more rarely 

 three-sided or five-sided meshes. The somewhat thickened nodes of intersection are 

 provided with rough flat papillary rounded swellings. It seems to me noteworthy that on 

 the (outer) dennal as well as on the gastral surface of the dictyonal framework the 

 nodes of intersection which are here very richly provided with protuberant papilhv;, are 



