156 THE VOYAGE OF H.M.S. CHALLENGER. 



Scirpearella gracilis, u. sp. (PI. XXXI. figs. 1, la; PI. XXXIV. fig. 6). 



The colony is simple (as far as can be judged from the few fragments collected). 

 These belong apparently to two separate colonies. The more perfect of these measures 

 1330 mm. in height, with a diameter, including the coenenchyma, at the widest (basal ?) 

 portion of 2"5 mm., but tapering to the dimensions of a fine thread. Among the smaller 

 frao-ments there is a terminal piece which ends in an acute apex, just below which are 

 two poljrps, opposite to one another; the axis at their base measures 1 mm. in diameter. 



The axis is calcareous, very brittle ; in the older portion of the stem it is compressed, 

 with a broad diameter of 1"5 mm. and a short diameter of 1 mm. On its broader 

 surfaces it is grooved. The polyps are crowded on the stem in four rows, the polyps 

 in each row alternating with those in the next row, so as to give a more or less spiral 

 arrangement to the polyp colony. This arrangement is sometimes obscured by the 

 addition of young polyps between the older ones. The polyps are retractile, leaving 

 prominent nipple-like verrucse. The tentacles are first drawn together and in, then the 

 upper portion of the polyp-body becomes invaginated ; then the walls of the verrucae 

 are drawn together, leaving a prominence, with a basal diameter of from 1 to 1'5 mm. 

 and about 1 mm. in height. On drying, these verrucse often become wrinkled. Towards 

 the apex of the stem the polyps are arranged in three rows, and at the very apex they 

 are opposite. 



The coenenchyma is moderately thick, it and the verrucae are rough, with a layer of 

 spiny or warty double clubs ; beneath these and in the bodies of the polyps are some 

 spiny spindles and stellate forms ; minute needle-shaped spicules with toothed edges, 

 and mixed with some stellate forms, occur in and at the base of the tentacles. 



The spicules measure as follows: — Warty spindles 0"l-0"04 ; "12-0 "06 mm. ; spiny 

 spindles 0-16-0-06 ; 0-14-0-05 ; 0-12-0-02 mm.; double clubs 0-08-0-04 ; 0-1-0-04 

 mm.; stellate forms 0-06-0-06 ; 0-1-0-08 mm.; needles 0-04-0-02 ; 0-06-0-02 mm. 



The colour in spirits is a brownish-white. 



Habitat. — Station 177, oif the New Hebrides; depth, 130 fathoms; bottom, 

 volcanic sand. 



This species and the preceding were taken at the same haul of the dredge, from a 

 depth of 130 fathoms; although no doubt closely related forms, there seem sufiicient 

 difi"erences to justify their being for the present treated as distinct. 



Scirpearella moniliforme, n. sp. (PI. XXXIV. fig. 8). 



In two specimens the colony seems simple, in a third, and that the largest, it has 

 a single branch. In this latter the axis is attached by a disc, 15 by 10 mm., and it has a 

 total length of 505 mm. The branch comes ofi" at a height of 215 mm. from the base. 



