OK LITTLE-KNOWN COMATULiE. 517 



yet to determiuo the range of variation. Such are the specimens 

 brought by Professor Semper from Bohol, and formerly referred 

 to by myself as Act. solaris^K These have keels on the basal joints 

 of the pinnules borne by the second and following brachials, and 

 much less massive arm- and pinnule-joints. The Asterias pecti- 

 nata, Linu.t, has traces of keels on the basal joints of both the 

 fir,st pinnules, while those of the next pair are strongly keeled. 

 In a couple of small specimens from the voyage of Peron and 

 Lesueur, which I found in the Paris Museum, the pinnules on the 

 second and fourth brachials have keeled lower joints, but there is 

 hardly any trace of this in the third pinnule ; while in Acfino- 

 metra affinis, Liitk. MS., from Java (Copenhagen Museum), the 

 first three pinnules have strong keels, and there are lesser ones on 

 the next pair. The Miilleriau types Comatula purjpurea, C. hra- 

 cliiolata, and C. rosea all belong to this " Solaris group." In the first 

 named, only the third pinnule has any keeled joints. The other 

 two species were regarded by Midler as possibly identical, a view 

 in which I entirely concur. In this type, which will therefore 

 have to be known as Actinometra rosea, the basal joints of the 

 first six pinnules are not specially marked, while the arm-bases 

 have tubercles at the junction of the joints, alternately on the 

 inner and outer sides. 



It will be a matter of no little difiiculty to determine the exact 

 mutual relations of these various forms, which all agree with Act. 

 Solaris in the syzygial union of the two outer radials. The greater 

 part of them are unfortunately dry and in a very fragmentary con- 

 dition, as are Midler's original specimens of Act. Solaris, on which 

 account I have thought it desirable to redescribe the type from 

 the fine spirit-specimen in the Hamburg Museum. 



2. AcTixoMETBA soBUSTA, Lutkcn, MS. 



Centrodorsal a low flattened disk 7 mm. wide, bearing a sino-le 

 or partially double row of 20-25 marginal cirri. These have 

 about 23 joints, of which the first three or four are wider than 

 long, and the following ones about square, or a trifle longer 

 than wide, decreasing slightly towards the end ; the penultimate 

 has a small opposing spine. 



Three radials visible ; the second short, trapezoidal, closely 

 united laterally, and united by syzygy at their wider distal edges 

 to the triangular axillaries, which are t-wice their length. 

 * Trans. Linn. Soc, 2nd ser., Zool. vol. ii. pp. 62 scq. 

 t ' Systema Natiu'tc,' eel. x. torn. ii. p. 063. 



