EEPORT ON THE ALCYONAEIA. 257 



line of the ribbing while towards the grooves they decrease in size. The rough spindles are 

 continued on the retractile portion of the pol)i5 wall, but they are there smaller and less 

 thickly set in the mesoderm. Thick, warty, transversely disposed spindles form a ring 

 under the base of the tentacles, while some spindles are continued on to the tips of the 

 tentacles ; these spindles measure O'l to O'lS mm. in length, with a diameter of 0"07 mm. 

 They are closely packed, but are not continued into the pinnae. In the wall of the 

 oesophageal tube scattered spicules also occur. In the wall of the stolons the spindles 

 become smaller, more delicate, and more sparsely beset with warts ; the spicules are 

 often slightly curved, but even here they form a thick layer. They measure 0'4 mm. in 

 length by 0"04 mm. in breadth. 



The colour of the colony as preserved in spirit is white. 



The species is distinguished from all related forms by the marked development of the 

 calyx. 



Habitat— Station 23, lat. 18° 24' N., long. 63° 28' W.; near Sombrero Island, West 

 Indies ; depth, 450 fathoms. 



B. Membrrmipoda. 



Clavidaria elongata, n. sp. (PI. XLII. fig. 11). 



The polyps rise from a thin basal membrane which covers a dead univalve shell. 

 They attain a height of 12 mm., and occur in part singly, in part in groups. The 

 individual polyps are narrowed superiorly, but are swollen out at the base. The wall 

 of the calyx is somewhat flabby. 



The membrane which contains the endoderm canals is thin, slightly stretched, and 

 filled with spicules. The polyps spring especially from its margin, but are few in 

 number. Each includes a calyx portion, with completely retractile tentacles and an 

 oesophageal region. The calyx portion is about 12 mm. in height; near the somewhat 

 thinner base it expands to a thickness of 4 mm., while superiorly it measures but 

 3 mm. The wall is rough owing to spiny spicules which are embedded in it, but it is not 

 rigid, rather in fact flabby and yielding. Distinct broad grooves run from the base to 

 the oral region ; between these the wall shows eight broad and slightly projecting ridges ; 

 when the polyps are retracted the oral region presents the form of an eight-rayed star. 



The tentacles, which are provided with spicules, are folded together over the oral 

 disc, and by the infolding of the wall below the oral region they are partly drawn into 

 the calyx. 



Spicules are embedded in the calyx ribs in longitudinal bundles ; the)' are bright 

 silvery spindles, slightly curved, and with a tendency to assume a club-shape by being 

 slightly thickened and truncated at one end. They .are beset by sharp somewhat distant 

 spines. Their length and breadth vary, and are respectively 0"83 and 0'042, 



(zoor,. CHALL. EXP. — PART Lxiv. — 1889.) Sss 33 



