222 Records of the Indian Museum. [Vol. IX, 



distal parts of the arms there are two tentacle papillae close to each 

 tentacle. Text-fig. 2 c shows a tentacle hook from the thinner part 

 of the arm. A girdle hook is shown in text- fig. 2a-b. 



It is one of my misfortunes that I have only been able to com- 

 pare this specimen with one other member of this genus, namely 

 with A.exiguus (Lamarck)=G. cornutus, Koehler (3). From this 

 it differs in having more than one conical tuberosity on each 

 radial shield. From A. euryale (Retzius), it differs in having 

 numerous tuberosities in the inter-brachial regions on the dorsum 

 of the disc.^ 



The specimen examined shows points of resemblance to A. 

 ludwigi (Doderlein) (4). Both have well developed tuberosities on 

 the radial shields. A. ludwigi, however, differs in having no 

 tuberosities on the arms and having its madreporite projecting 

 into the soft inter-brachial area. But for these differences (which 

 might not obtain in an example of A. ludwigi which measured 

 more than 7 mm. in the diameter of the disc) I feel inclined to 

 include this specimeii in that species. But it agrees sufficiently 

 well with that variety of A. dofleini, Doderlein, which has conical 

 tuberosities. It shows a general resemblance to the example 

 Doderlein figures in his review of Japanese Ophiuroids (5, plate 

 4, fig. 4), but has the tuberosities on the disc much more 

 prominent. 



Trichaster elegans, lyudwig, 1878. 



(PI. xiii, figs. 3—4,) 



This species (Regd. no. ZEV '"•—), founded on a single speci- 

 men from the Bay of Bengal, has apparently not been met with 

 since Ludwig (2) published his description. Doderlein (5) has 

 concluded that I^udwig's specimen was but a young example of 

 T. palmiferus (Lamarck). For these two reasons it may be well 

 to give a short description of a specimen recently obtained by the 

 R.I.M.S. ''Investigator" in the neighbourhood of the Mergui 

 Archipelago (Station No. 533. Lat. i2°55'5o" N., Long. 96°5i' 50" 

 E.). 



This example is considerably larger than the one described by 

 Ludwig, its linear measurements being nearly twice as great. 

 It was living on a sandy bottom at 58 fathoms depth, and its 

 general colour was a sandy grey on the upper and almost white 

 on the lower surface. The centre of the disc, however, was of a 

 very dark olive green, and this same colour extended as a band to 

 each inter-brachial margin of the disc, and also in the same man- 

 ner along the dorsum of each arm. On the arms the intensity of 

 the colour gradually diminished through brown into the general 

 grey colour, so that after the first bifurcation, the dark streak 

 was hardly noticeable. 



1 The only figure of this species with which I have been able to compare the 

 specimen is that given by L. Agassiz (i) under the name of Gorgonocephalus verru- 

 eosus. 



