XIII. A NOTE ON CERTAIN OPHIUROIDS IN THE INDIAN MUSEUM. By T. L. BOMFORD, Capt., I. M.S., OfficiaHng Surgeon-Naturalist on the R.I. M.S. " Investigator.'" (Plate xiii.) This note deals with four species obtained by the R.I.M.S. ''Investigator." Three are members of the Gorgonocephalinae, while the fourth is a Trichaster. The generic names employed are in accordance with the definitions given by Professor Doderlein in his recent review of the Euryalae (5). Astrodendrum laevigatum (Koehler), 1897. This specimen (Regd. no. zEv ~^), from Station No. 284, is considerably larger than the type described and figured by Fig. I. — Gix^e: hooks oi Astrodendrum laevigatum, x 200. Koehler (3) as Gorgonocephalus laevigatas. It was obtained off the east coast of Ceylon from a depth of 506 fathoms. The radial shields on the dorsum of the disc are developed irregularly, and some are imperfect. In addition they are bent, forming a 'dorsal loop (resembling in outline a Geometrid cater-pillar ) : this, being probably due to the shrinkage of the disc aft^r immersion in spirit, indicates the weakness of the shields.