REPORT ON THE ASTEROIDEA. 257 
towards the tip, is obtuse there. This spinelet is normally directed over the furrow and 
separates the adjacent tube-feet. The other two spinelets are subequal, are a little longer 
than the furrow spinelets, measuring at the base of the ray 4 mm., and are delicate, 
cylindrical, and tapering, but truncate at the tip, and often with a faint tendency to 
flare. On the aboral side of the outermost spine is one very small, short, cilia-like spinelet. 
The mouth-plates are elongate, narrow, and strongly keeled; their armature consists 
of a marginal series which extends the whole length of the plate, very small and papilli- 
form along the line of union with the adambulacral plate proper, and only the inner three 
or four on the free part of the margin larger and spiniform ; the innermost two on each 
plate are close together, often flattened and apposed, and form what may perhaps be 
looked upon as an incipient pedicellarian apparatus, which is directed horizontally over 
the actinostome at an angle of 45° to the median radial line. On the actinal surface of 
the plate is a lineal series of spinelets, robust and large along the greater part of the plate, 
but diminishing in size as they recede from the mouth, becoming rapidly mere small 
papille at the outer end of the plate. 
In the very limited actinal interradial area there are generally two or three additional 
pedicellarize exactly similar to those on the small intermediate plate which separates the 
infero-marginal and adambulacral plates along the ray. 
The madreporiform body is situated very near the margin, and is usually hidden by 
paxille ; its appearance is more or less spongiform rather than “ madreporiform ;” and 
the striations are coarse, with definite foramina distinctly visible here and there. 
Colour in alcohol, a warm shade of brown over the paxillar area, becoming nearly brick 
red at the extremity of the ray ; the terminal or ocular plate white. The centre of the 
disk and a narrow well-defined band traversing the median abactinal line of the ray are 
marked with a much darker colour, approaching dark purple, which gives a very striking 
appearance. Actinal surface a bleached yellowish white. 
Localities. —Simon’s Bay, Cape of Good Hope. 
“ Porcupine” Expedition : 
Station 36. 1870. In the Strait of Gibraltar, off the coast of Morocco. Lat. 35° 35’ 
N., long. 6° 26’ W. Depth 128 fathoms. Bottom temperature 12°°9 C.; surface 
temperature 23°°8 C. 
Remarks.—This species is nearly allied to Lwidia sarsii of the North Atlantic, of 
which it is unquestionably the representative. Both are five-rayed forms, but Luidia 
africana is of much larger size, and the rays taper gradually from the base to the tip, 
giving them a very pointed and attenuate appearance. The paxille on the median portion 
of the rays are very much smaller than in Luidia swrsii, and the central granule is less 
prominent than in that form throughout. In Luidia africana the uppermost or lateral 
spine on the infero-marginal plates is the largest, whereas in the northern species this is 
generally smaller. In like manner, the outermost of the three spines on the adambulacral 
(ZOOL. CHALL. EXP.—PART LI.—1888.) 33 
