REPORT ON THE ALCYONARIA. 147 



white branches. The enlarged figure of a polyp represents a thin central horny axis with 

 a rather thick ccenenchyma and a semi-retracted polyp, possibly a Murieeid. 



The enlarged figure given of Swiftia exserta, D. and M. {loc. cit., pi. xi. fig. 5), shows 

 a thin ccenenchyma with a thick axis, and we read " Nous ne donnons pas la description 

 de cette espfece, qui a dejh, ete publiee par les auteurs." Good specimens of Thesea 

 guadalupensis, D. and M., are still in the Museum at Turin, and this form would appear 

 to be near Acis, D. and M. The axis is horny, not effervescing with acids ; polyps 

 prominent, and the ccenenchyma is loaded with very large irregular spicules. 



A new species of Thesea has been described by Verrill,^ Thesea gemmata, which the 

 author says resembles in external characters Gorgonia exserta as figured by Ellis and 

 Solander, which latter Duchassaing and Michelotti refer to t\\eiv Swiftia exserta, but it has 

 more prominent verrucse. Its spicules are however very different from those of Thesea 

 guadalupensis,^. and M. The Gorgonia richardii, D. andM., bears some resemblance 

 to it in external appearance, so far as one can judge from the figures, but has stouter 

 branches and more cylindrical verrucse. 



It seems desirable to mention these facts here, for Thesea gemmata, Verrill, appears 

 to have a likeness to a very interesting species of Gorgonid found by the Challenger 

 Expedition at Banda, for which we have been obliged to make the above new genua, 

 Verrill's species was obtained in deep water off St. Croix, West Indies. 



Platycaulos danielsseni, n. sp. (PI. XXXIII. fig. 8 ; PI. XXXV. figs. 1, la). 



The colony is branched, the branches arising in the one plane ; both the stem and 

 branches are compressed. The total height of the colony is 325 mm., with a basal axial 

 diameter of 8 mm. in its broad and of 4 mm. in its short diameter. The colony was 

 attached by a broad base, the remains of which are preserved. The branches rise at 

 intervals of about 10 mm., at a height of 95 mm. from the base the broad diameter of the 

 axis is 6 mm. The first six branches from the left side of the stem arc short, from 15 to 

 20 mm. in length, simple or feebly branched. The seventh extends to a length of 170 mm. 

 with a breadth of 5 mm., and divides into a number of smaller branches which again divide ; 

 between two of these there is an anastomosis. At an interval of 50 mm. another large 

 branch is given off, which also divides as in the former case ; between the two large 

 branches and between the second branch and the apex of the stem there are several 

 small twigs ; the lengths of these diminish as they approach the summit. The ramification 

 of the left side of the stem is of the same nature, but all the branches are smaller than 

 those of the opposite side, not exceeding 130 mm. in length. One of the smaller 

 branches has become anastomosed with the main axis. The ccenenchyma is moderate in 

 thickness, when dry it presents a roughened appearance owing to an outer layer of spiny 

 spindle-shaped spicules ; an inner layer contains both stellate and spindle-shaped spicules. 



1 Amer. Joum. Sci. and Arts, vol. xlviii. p. 428. 



