512 s. goto: 



less coarse. The dorsal surface is rendered markedly reticulate by the great 

 size and close approximation of the poriferous areas, two of which pass 

 along each side of every arm ; in the middle ofthe arm the second of tliese 

 may equal in length as much as haK the whole height of the arm ; some- 

 times the connecting j)i'ocesses of the ossicles become verj' delicate, when 

 tlie whole side of the aim appears to fonn a huge i)oriferous area. Spines 

 are very irregularly develo^^ed at the angle of the areas ; sometimes they 

 are distributed so regularly that one may almost speak of a regular 

 row of spines running on either side of the lophial series ; in other cases 

 they are completely absent. This haj^pens sometimes also to the sj)ines of 

 the lopliial ridge itself, but they are ordinarily very well developed, as are, 

 too, the ax3ical spines and the spines that stand below them on the sloping 

 sides of the disk. The granulation on the dorsal spines and ossicles is very 

 coarse and extends sometimes quite to the tips of the spines. Madreporic 

 plate rather small, not conspicuous. 



" Colom* (when diy) — lower sm-face reddish, upper reddish where the 

 gi-anules are developed, with gi'ey poriferous areas ; in some cases the dried 

 S]_)ecimens are ahnost white, but tliis may be due to the mode of drying. 



" The above description has been drawn up from a set of five speci- 

 mens, wliich were collected at the same time and place (between tide- 

 marks, at the Mozambique, in May 1882) by Dr. Coppingek, H.M.S. 

 , Alert,' and illustrate the exactness of the statement of Dr. von Maetrns : — 

 ' Alle diese Variationen kreuzen sich so sehr dm'cheinander, dass man 

 darnach keine irgendwie bestimmbaren Lokalvarietäten aufstellen kann.' 

 The variations are so marked that it seems to be impossible to follow Dr. 

 VON Martens in estabhshing definite ' varieties.' The exact state of the 

 case is, I think, this. The strength of the marginal and ventral i)lates, 

 wdth their coarse gi'anulation, is sufficient for the safety of the Starfish ; 

 the s^Dines are additional defences that are not constantly needed, and are 

 develoi3ed more according to the conditions of individual environment than 

 in obedience to the necessities of the species. They are organs which have 

 l)egim to disapjDear, and their importance to their i^ossessor may be judged 

 of by the extent to which they vary in niunber and size on the different 



