746 



WSo:- " THETIS " SCIKNTIFIC RESULTS. 



An e^aminatioti of the type of Miillei's Comatula cuDiingii 

 lias shown it to be a young specimen of this species. 



COMATULA. PURPUREA (J. Milller). 

 Alecto jnirjnirea, 1843, J. Miiller, Archiv fiir Naturgesch., 1843, 



i., p. 132 (Australia); 1910, A. H. Clark, Proc. Biol, Soc. 



Washington, yol. 23, pp. 95-98 (fig.) {detailed description of 



the type specimeii). 

 Actino?netra pectinata {•p^rt), 1884, Bell, Rep. Zool. Coll. H.M.S. 



"Alert," p. 165. — 1888, P. H. Carpenter, "Challenger" 



Reports, Zool., vol. 26, p. 284, pi. liii., fig. 15. 

 Differential Characters. — This species is vei"}' like C. pectinata, 

 but may be at once distinguished by the curious arrangement of 

 the cirri ; these are segregated in the interradial angles where they 

 occur singly or in pairs, so that they are from five to ten in 

 number. The size of C. purpurea is usually much less than that 

 ot G. pectinata. 



Through the kindness of the authorities of the Berlin Museum 

 I was enabled to compare the specimens recorded below directly 

 with Professor M tiller's original type. 



Specimens in the Australian Mtiseam Collection. — Murray 

 Island, Torres Strait — 'Thirteen specimens ; the cirri are v-x 

 (usually nearer the latter), 9-12 (usually 11-12), 6 mm. long; as 

 in C. pectinata they are of two types which are quite distinct, a 

 prinntive type in which the segments, except the basal two, are 

 subequal in length and the distal are not compressed laterally, 

 and a more advanced type in which the distal segments are 

 shorter than the proximal, and are laterally compressed ; the 

 arms are from 40 mm. to 50 mm. long ; the median dorsal surface 

 from the sixth brachial outward is occupied by a delicate narrow 

 rounded ridge, more prominent than the similar ridge often seen 

 in C. pectinata. Port Denison — On specimen with arms 80 mm. 

 long and cirri viii., 10-12, 8 mm. to 10 mm. long. No locality — 

 One fine large specimen with arms 120 mm. long and cirri vii., 

 14-15, 9 mm. to 11 mm. long. 



Additio7ial Australian Records. — This species was not diflfer- 

 ■entiated from C pectinata either by Bell or by Carpenter. At 

 the British Museum I examined specimens from Dundas Strait, 

 in 17 fathoms; from Torres Strait ; and from Dimes Island, New 

 Ouinea. It is abundant at Shark Bay. 



Subfamily COMASTERIN^, A. H. Clark. 

 Genus C O M A S T E R, L. Agassiz. 

 (Jomaster, 1836, L. Agassiz, Mem. Soc. sci. nat. Neuchatel, vol I, 

 p. 193. (Comatula '>nidtiradiata, Lamarck, 1816 [not Asterias 

 multiradiata, Linnaeus, 1758]=i4?6cto multifida, J. Miiller, 

 1841). 



