The Marine Fauna of the Mergui Archipelago. 157 



Family Ophiothricid^;. 



(7) Ophiothrix foveolata Marktanner-Turneretscher, p. 161. 



(8) „ martensi Lyman, p. 162. 



(9) „ stelligera Lyman, p. 163. 



(10) „ exigua Lyman, p. 164 



(11) „ hirsuta Miiller et Troschel, p. 164. 



(12) Ophiocampis pelhicida Duncan, p. 165. 



(13) Ophiocnemis marmorata (Lamarck), p. 166. 



(14) Ophiopteron gymnatum, nov. sp., p. 167. 



(15) Lutkenia cataphracta Brock, p. 170. 



2. CLADOPHIURiE. 

 Family Euryalid^e. 



(1) Bury ale studeri Loriol, p. 171. 



(2) Astrcphyton clavatum Lyman, p. 171. 



III.— EEMAEKS ON THE SPECIES. 



1. ZYG0PHIUR5I. 



(1) Pectinura gorgonia Liitken. 



The following notes are based on an examination of fifty-five examples 

 of this species from four stations. 



The disc is distinctly pentagonal, with a notch for the insertion of each of 

 the arms, which, on the dorsal side, are ridged rather than " cylindrical," as is 

 stated by Lyman (1882). While the oval radial shields are very distinct, the 

 other scattered and smaller non-granulated disc-plates do not stand out so 

 clearly as is indicated in Koehler's diagram (1900). A " specific " character 

 is the presence of a couple of pores between the first and second ventral arm- 

 plates. But in three of my specimens, which are the largest in the collection, 

 having a disc-diameter of about 19 mm. and an arm-length of over 85 mm., 

 there is also found a pair of smaller pores between the second and third 

 ventral arm-plates. The arms carry on each side seven smooth flattened 

 spines, which are less than the length of a lateral arm-plate, and the base of 

 the lowest arm-spine is overlapped by the upper of two tentacle-scales. 

 There is an elongated genital opening which stretches to the margin of the 

 disc from the inner corner of the supplementary plate just outside the mouth- 

 shield. My examples are creamy-white below, and of a greenish-grey colour 

 on the upper surface, while every alternate four or five joints on the upper 

 side of the arms are ringed with a darker green. 



Localities. — St. IX., Between Bentinck Island and Courts Island, 12 to 26 

 fathoms, sand and coral (five examples). St. XVIL, West of Sir John 



