1906.] ALCYONARIANS FROM ZANZIBAR. 431 



Wrightella variabilis, sp. n. (Plate XXYIII. figs. 3-9.) 



The collection included a considerable number of small delicate 

 Melitodid?e, of beautiful and appai'ently variable coloration. The 

 branches tend to be compressed ; they lie for the most part in one 

 plane ; the verrucpe are for the most part lateral ; the spicules are 

 warty spindles, straight and curved, sometimes kneed, and clubs 

 with warty expanded ends which are not foliate enough to be 

 called " Blattkeulen." At the same time, the specimens seem 

 nearer the genvis Wi'ightella than any othei-, and till a large 

 number of specimens is available it seems convenient to combine 

 the various specimens in this collection under the common title 

 W. variabilis. They differ not only in colour, but in respect 

 to the proportions and warts of their spindles and clubs. Some 

 of the colour-schemes of these closely-related forms are shown in 

 Plate XXVIIT. We may readilj^ distinguish : («) a form with 

 a variable combination of red and colourless spicules, with more 

 substantial and shoi'ter branches than the others and a closer 

 approach to W. erythrcea ; (h) a foi-m with yellow internodes and 

 the usual brown nodes appearing as red ; (c) a salmon-coloured 

 form ; (d) a crimson form with yellow verrucas ; and (e) a reddish- 

 brown form with red verrucse. 



Locality. Wasin, among coral, low tide. 



Order IV. AXIFERA G. von Koch. 

 Family Gorgonid^. 



Leptogorgia ochracea, sp. n. 

 Lophogorgia crista Mobiits. 



,, liitkeni Wright & Studer. 



Family Gorgonid^. 

 Leptogorgia ochracea, sp. n. (Plate XXIX. fig. 1.) 



This apparently new species of Leptogorgia is represented by 

 a beautiful diy specimen, 18-5 centims. in height by 15 in 

 maximum breadth. It has a bright oclireous-yellow colour and 

 expands for the most pait in one plane with several anastomoses. 

 The disc of attachment has been separated fi'om the substratum 

 and has been overgi-own almost entirely by the ccenenchyma and 

 a Polyzoon. 



From the basal expansion, about 22 mm. in diameter and 

 9 mm. in height, there rises a main stem, 4 mm. in basal 

 diameter, which gives ofl' numerous branches. Jvist at the base 

 a large branch is given off, so nearly equal to the main stem in 

 diameter (3 mm.) that it might be i-egarded as of equal im- 

 portance. The main stem is at first circular, but soon becomes 

 flattened in the plane of expansion ; the larger branches are also 

 flattened, but the twigs are cylindrical. There is no particular 

 arrangement of brandies, but the tendency to arise on one side, 

 i. e. towards vacant space, is well-marked. The tips of the 



