PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 249 



nearly to the brachials, alternating with small, delicate, and very irregular fenestrated 

 plates lying above the sacculi. 



The color of specimens at Rhodes is given by Tortonese, 1946, as varying from 

 yellow, coral red, chocolate brown, to whitish with brown spots and rings. Miilleger, 

 1951, says that it may be anything from uniform white to dark red or brown. 



Notes. In the specimens collected by the Washington in northern Sardinia, Bal- 

 delli found the number of the cirrus segments to range from 17 to 30; the average of 

 numerous counts was 23. 



He gives the arrangement of the syzygial pairs on 9 arms in which this was irregular, 

 as follows: 



Regular disposition 



Brachials 3 + 4, 9 + 10, 14+15, 18 + 19, 22 + 23, . . . 

 Irregular disposition 



Brachials 3+4, 7 + 8, 11 + 12, 15+16, 19 + 20, 23 + 24. 

 " 3+4,9+10,16 + 17,20 + 21,24+25. 



3+4,9 + 10,14+15,22+23. 



3+4,9 + 10,15 + 16,19+20. 

 " 3+4,9 + 10,13 + 14,46+47. 



3+4,9 + 10,18 + 19. 



3+4, 11 + 12, 16+17. 



3+4,12 + 13,16 + 17,20+21,24 + 25. 



3+4, 9+10, 11 + 12, 16+17. 



Tortonese (1935) has recorded some specimens from the Gulf of Genoa with up 

 to 29 cirrus segments but comments that there are rarely more than 20. 



Abnormal specimen. With two disks : In a specimen of this species from Naples 

 Mr. Herbert C. Chad wick found a supernumerary disk. 



The true disk, which measured 7.5 mm. in diameter, was in all respects quite normal 

 except for the displacement of one of the ambulacral grooves. On its oro-lateral 

 border it bore a small rounded body roughly spherical in shape and about 3 mm. in 

 diameter, which was attached to the normal disk by a sort of stalk which gradually 

 narrowed from the oral to the aboral surface. Near the center of its oral surface was a 

 well developed mouth, fringed with tentacles, from which 5 ambulacral grooves radiated 

 just as they do in the disk of a normal Antedon; of these 4 could with little difficulty 

 be traced outward to the aboral surface. The remaining one ran along the stalk of 

 attachment to the normal disk and joined the ambulacral grooves of the pair of arms 

 nearest to it, immediately after crossing the line of junction of the two disks. On 

 the aboral surface the anus appeared as a minute crescent-shaped aperture close to 

 which was a minute scarcely distinguishable pore, another rather large aperture appear- 

 ing on the summit of the funnel-shaped projection. 



The body cavities of the two disks intercommunicated freely through the stalk 

 uniting them, but their alimentary canals were quite distinct. The alimentary canal 

 of the supernumerary disk was well developed and contained food. The ambulacral 

 system was well marked, and presented a feature of special interest. The minute 

 pore close to the anus opened into a canal-like space which traversed the body wall 

 for a distance equal to the thickness of 17 sections and again communicated with 



