(54 MR W. PERCY SLADEN ON THE 



place the solitary specimen as a variety of P. militaris until further material is 

 available — a course which is sufficient to identify the form, and at the same time 

 indicate the nearest specific affinities. 



The variety is characterised by the following points : — The great length and 

 narrowness of the rays ; R > 3 r ; R = 58 to 60 mm., r= 18 mm. ; breadth of a ray 

 at the base, 18 to 22 mm. extreme measure. The dorsal paxillse appear usually 

 to have one of their spinelets much more robust than the two or three com- 

 panion spinelets, which are remarkably fine and delicate, and the tips of the 

 spinelets can scarcely be said to protrude through the supradorsal membrane, 

 notwithstanding that this latter is placed rather loosely upon them, and much 

 wrinkled. Two or three lineal series of paxillae are more or less clearly distin- 

 guishable along the sides of the rays. On the actinal surface the segmental 

 apertures are remarkably large, and the aperture-papillae are much broader and 

 more robust at their proximal portion than in P. militaris. In the ambulacral 

 spines the three inner spines of each transverse comb form a line oblique to the 

 furrow, the comb being curved aborally at the margin of the furrow, and the 

 position of these spines upon the adambulacral plate being also oblique in rela- 

 tion to the plane of the ray. The actino-lateral spines are very short, and the 

 outer portion of the web which proceeds from the outermost ambulacral spine, 

 i.e., the membranous continuation of the transverse comb upon the actinal 

 membrane, is much more prominent than in the typical form of the species, and 

 extends up to the margin of the lateral fringe. Although these differences may 

 appear insignificant verbally, they produce when combined a striking facies, the 

 characters of which can hardly be explained, as being simply the modifications 

 of the normal form consequent on the conditions of a deep water habitat, since 

 the example of P. militaris from 530 fathoms (Station 2), recorded above, differs 

 in no way from the normal form. 



3. Archaster tenuispinus (Duben and Koren), Sars. 



Station 9. August 23, 1882. Lat. 60° 5' N., long. 6° 21' W. 

 Depth, 608 fathoms ; bottom temperature, 30° Fahr. 



4. Archaster bi/rons, Wyville Thomson. 



Station 10. August 24, 1882. Lat. 59° 40' N., long. 7° 21' W. 

 Depth, 516 fathoms ; bottom temperature, 46° Fahr. 

 Station 11. August 28, 1882. Lat, 59° 29' N., long. 7° 13' W. 

 Depth, 555 fathoms ; bottom temperature, 45° 5 Fahr. 



5. Astropecten Andromeda, Midler and Troschel. 



Station 10. August 24, 1882. Lat. 59° 40' N., long. 7° 21' W. 

 Depth, 516 fathoms ; bottom temperature, 46° Fahr. 



