PART 5 



A MONOGRAPH OF THE EXISTING CRLNOIDS 



159 



Table 4. — Measurements of some specimens of Antedon incommoda, respectively three syntypes of 

 A. incommoda austmi from northwest Australia, five syntypes and three other specimens of A. in- 

 commoda mcommoda from Port Phillip, Victoria, and the types of Compsometra laccrtosa from 

 Port Jackson summarized for comparison 



Description of the types of lacertosa. — Centrodorsal discoidal, rather thin, with 

 a broad flat polar area nearly or quite 2 mm. in diameter; cirrus sockets arranged in 

 two very closely crowded more or less irregular marginal rows. 



Cirri XXXIV-XXXVI, 9-12 (usually 10), 7 nmi. long; first segment very short, 

 second nearly or quite as long as broad, fourth and fifth the longest, about half again 

 as long as the median diameter; followang segments gradually decrease in length, so 

 that the last two are about as long as broad; opposing spine minute, slender, sub- 

 terminal, directed slightly forward; terminal claw long, nearly twice as long as the 

 penultimate segment, evenly tapering and moderately and evenly curved; second 

 and following segments slightly constricted centrall3% this character gradually dis- 

 appearing distallj' as the segments become shorter; longer proximal segments roimd- 

 ed in cross section and comparatively narrow in lateral view, the shorter outer seg- 

 ments becoming laterally flattened and therefore appearing broader in lateral view. 



Distal edge of radials even \vith the border of the centrodorsal. 



IBri very short, about four times as broad as long, shghtly trapezoidal. The IBrj 

 (axiUaries) are ahuost triangular, the lateral edges, which are shghtly shorter than those 

 of the IBri, making M-ith the sides of that ossicle almost a right angle; in shape they 

 are about as broad as long, mth the distal angle considerably produced. 



Arms 10, from 60 to 65 mm. long, rather stout in the basal third but becoming 

 exceedingly slender distaUy; fu-st brachial short, almost oblong, from two to two and 

 a half times as broad as long in the median line, barely in contact basally interiorly, 

 the diverging interior edges making a very broadly obtuse angle; second brachial 

 umch larger, almost triangular, about as broad as the greatest length; first syzj-gial 

 pair (third and fourth brachials) wedge-shaped, twace as long interiorl3' as exteriorly, 

 about as broad as the interior length; foUo\ving three brachials about twice as broad 

 as the median length, slightly wedge-shaped, the brachials then become very obhquely 

 wedge-shaped, almost triangular, about as broad as long, furtlier out on the arm 



