NO. 24 FOUR NEW BRITTLESTARS CLARK 7 



lateral edges of the side arm plates diverge slightly so that the lateral 

 profiles of the arm are somewhat serrate. 



The arm spines are two in number, the lower situated on the lateral 

 carinate ridge and the other just above and almost in contact with it. 

 In the first pair the lower spine is about equal to the length of the 

 succeeding side arm plate, and the higher is about one-third again as 

 lung. In the second pair the spines are larger and longer; the lower 

 is nearly equal in length to two side arm plates, and the ui)per is 

 similar, but longer, equal in length to about two and one-half side 

 arm plates. The spines of the succeeding pairs decrease in length, 

 those of the ninth and following pairs being scarcely longer than a 

 side arm plate. On the outer portion of the arms the spines are simi- 

 lar, from one-third to one-half again as long as a side arm plate, the 

 upper slightly the longer. 



The first tentacle pore has two large rounded tentacle scales situ- 

 ated distal to it. The first brachial tentacle pore has two large rounded 

 tentacle scales situated on the abradial side. The pores following have 

 each a single large and conspicuous tentacle scale. At the l)ase of the 

 arms this is about twice as long as broad with the proximal end 

 broadly and evenly rounded, the sides parallel or slightly convergent, 

 and the distal end deeply notched. Outwardly the tentacle scale in- 

 creases in relative length, becoming about four times as long as broad 

 with a deep and narrow distal notch. Here it is about as long as the 

 distance from its base to the distal edge of the under arm plate next 

 proximal to it. The tentacle scale is thin and strongly curved so that 

 it is approximately one-quarter of a hollow cylinder of equal length. 

 This has the effect of making the outer borders appear much more 

 opaque and dense than the central glassy strip which, in connection 

 with the sharp and produced distal angles, gives the general effect of 

 two spiniform tentacle scales situated side by side. 



EXPLANATION OF PLATES 

 Plate i 



Fig. I. OphJoviusium regulare, n. sp., the type specimen (U.S.N.M. no. E.5194) 



from Caroline station 45, aboral surface. X 3- 

 Fig. 2. Ophiomusiitm regulare, n. sp., the specimen shown in figure i, oral 



surface. X 3- 



Plate 2 



Fig. 3. Ophiumnsium rosaceum, n. sp., the type specimen (U.S.N.M. no. E.5196) 



from Caroline station loi, aboral surface. X 3- 

 Fig. 4. Ophiomusimn rosaceum, n. sp., the specimen shown in figure 3, oral 



surface. X 3- 



