no. 1808. RECENT AFRICAN CRINOIDS— CLARK. 41 



Cirri XXX-XLV, 10-13 (usually 11-12) 9 mm. to 11 mm. long; 

 first segment short, second not quite so long as broad, third twice as 

 long as broad, fourth about two and one-half times as long as the 

 proximal diameter; following segments gradually decreasing in 

 length so that the penultimate is less than one-third again as long as 

 broad; the elongated lower segments are slightly constricted cen- 

 trally, and the distal half of the cirrus is rather strongly flattened 

 laterally; opposing spine prominent, though small, sharp, sub- 

 terminal, more or less erect; terminal claw slightly longer than the 

 penultimate segment, rather stout and rather strongly curved. 



Radials even with the edge of the centrodorsal ; IBrj exceedingly 

 short and bandlike; IBr 2 triangular, twice as broad as long, the 

 anterior angle sharp, the middle of the posterior margin somewhat 

 produced proximally, the lateral angles extending considerably 

 beyond the anterolateral angles of the IBr^ 



Ten arms 30 mm. to 45 mm. long; first brachial very short, some- 

 what shorter interiorly than exteriorly, interiorly united basally; 

 second brachial much larger, irregularly quadrate; third and fourth 

 brachials (syzygial pair) somewhat longer interiorly than exteriorly, 

 about twice as broad as the interior length; following four brachials 

 approximately oblong, about three times as broad as long, then soon 

 becoming triangular, about as long as broad, and in the outer part of 

 the arm wedge shaped and longer than broad. 



Syzygies occur between the third and fourth brachials, again 

 between the ninth and tenth and fourteenth and fifteenth, and 

 distally at intervals of three oblique muscular articulations. 



P x small and slender, but somewhat stiffened, tapering evenly and 

 rather rapidly, 3.5 mm. long with twelve segments, most of which 

 are considerably elongated; P 2 similar, but somewhat smaller and 

 more slender, 2.7 mm. long with eleven segments; P 3 6 mm. to 7 mm. 

 long with eighteen to twenty segments, slender and flagellate; P 4 

 4 mm. long with thirteen segments, shorter than those of P 3 ; follow- 

 ing pinnules slowly increasing in length, the distal pinnules being 

 6 mm. to 7 mm. long and exceedingly slender. 



Locality. — Mauritius; the type, which is No. 5349 (part) Berlin 

 Museum, was collected by Professor Mobius. 



Madagascar; a specimen in the Paris Museum was collected here by 

 M. Grandidier in 1905. 



Remarks. — This species is most nearly related to I. nana of the 

 East Indies, but may at once be distinguished by its much stouter 

 cirri, the component segments of which are much less constricted 

 centrally, and by the larger P 1; which -is considerably stiffened. 



I had been aware of the occurrence of some species of this genus 

 on Mauritius for some time before I was able to examine any speci- 



