158 CEYLON PEAKL OYSTER REPORT. 



axillaries the 1st syzygy is in the 3rd brachial. The diameter of the 22 arms of the 

 specimen from Station LXVI. gradually increases from the 1st to about the 20th 

 brachial. 



Actinometra parvicirra (Muller) Plate, figs. 13, 14. 



Specimens of this well-known species were dredged at Stations IX.. XLL, XLVL, 

 LIV., LVIL, LXIIL, and LXIX. The number of arms varies from 10 in a specimen 

 from Station XLL and 11 in one from Station LVIL to 48 in one from Station IX. 

 So far as I am aware, no 10-armed specimen of this species has hitherto been 

 discovered ; and as the form and disposition of the 2nd and 3rd radials of the one 

 under notice differ markedly from the same parts in the other specimens in the 

 collection and from those figured in Carpenter's Report on the Comatulidse of the 

 " Challenger" Expedition, I have thought it worthy of illustration (fig. 13). It will 

 be seen that the disk is covered with minute scale-like plates (fig. 14), which, I 

 presume, are similar to those covering the disk of the specimen from Torres Straits, 

 mentioned by Carpenter. The specimens with 44 and 48 arms respectively 

 approach Actinometra rcgalis, Carp., in having no spines, or but feebly developed 

 ones, on the penultimate joints of the cirri, and in the close lateral contact of the 2nd 

 and 3rd radials and 1st distichals. Several distichal series consisting of two joints 

 occur in most of the specimens. The colour of one of the sjDecimens from 

 Station LXIX. is described in Professor Herdman's diary as being, when living, 

 "of a deep olive-brown with yellow tips to the pinnules, and having an olive-brown 

 species of Alplmus striped with grey living on it." Some of those from Station XLVL 

 were " dark purple," others " orange coloured." 



DESCRIPTION OF PLATE. 



Fig. 1. Base of an arm of Antedon xerrijiinna, with pinnules of 2nd, 4th, Gth, and 8th brachials. x 10. 



2. A cirrus of Antedon sernpinna. x 10. 



2a. Portion of same, viewed from the dorsal surface. x 10. 



,, 3. Antedon okelli, n. sp. x 4. 



,, 4. A cirrus of Antedon okelli. x 8. 



,, 5. Base of an arm of Antedon okelli, with pinnules of 2nd, 4th, Gth, 8th, and 10th brachials. x 10. 



6. A ray of Antedon reynaudi, with one series of distichals and an arm springing directly from the 



radial axillary, x 5. 



,, 7. A ray of Antedon reynaudi, with two series of distichals. x 5. 



8. A cirrus of Antedon reynaudi. x 5. 



,, 9. Distichal pinnule of Antedon reynaudi. x 5. 



10. Pinnule of 4th brachial of Antedon reynaudi. x 5. 



,, 11. Pinnule of 6th brachial of Antedon reynaudi. x 5. 



., 12. Portion of an arm of Antedon reynaudi, viewed from the dorsal surface. x 4. 



., 13. A 10-armed specimen of Actinometra jiarvicirra, viewed from the dorsal surface, x 8. 



,, 14. Disk of the same specimen, viewed from the ventral surface. x 8. 



