C^NOPEDINA MIRABILIS. 221 



Station 4178. Off Kawahioa Point, Niihau, H. I. Bott. temp. 43^? 319- 

 378 fathoms. Co. s., r., p. 



Station 4179. Off Kawahioa Point, Niihau, H. I. Bott. temp. 42^. 378- 

 426 fathoms. Co. s., r., p. 



Bathymetrical range, 256-1081 fathoms. Extremes of temperature, 46°(?j- 

 37.1°. 



Eleven specimens. 



Csenopedina mirabilis Mrtsn. 



Hemipedina mirabilis Doderlein, 1885. Arch. f. Naturg., Jahrg. LI, 1, p. 24. 

 Caenopedina mirabilis Mortensen, 1904. Dan. Exp. Siam: Ech., p. 34. 



Plates 91, figs. U-17; 105, fig. 8. 



This species has been very fully described by Doderlein (1906, "^'aldivia" 

 Ech., p. 174) and the pedicellariae have been discussed and figured by Mortensen 

 (1. c), so that there is httle to add, but as many of the "Albatross" specimens 

 are considerably larger than Doderlein's, there are a few points worth mention- 

 ing. The largest specimen is 22 mm. in diameter, and 11 mm. high; the 

 abactinal system is 11 mm. across and the actinostome 10 mm. There are 9 

 interambulacral plates and 14 ambulacral, in each column. The longest pri- 

 maries measure 27 mm. It will be noticed that the test is a little higher, the 

 abactinal system a little smaller, the number of coronal plates, especially 

 ambulacrals, somewhat larger and the primary spines a little shorter than in 

 the type but the differences are too trivial to be of importance. 



True tridentate pedicellariae seem to be very rare as only one was found, in 

 th« examination of five specimens, but the globiferous ones are abundant, and 

 conspicuous because of the very dark-colored glands on their valves. The latter 

 are about .30 mm. in length and have, as figured by Mortensen, a truncate 

 or rounded tip with a prominent tooth on each side. But ihey are quite 

 variable, for between tne two conspicuous teeth there are several others, which 

 are typically very minute, but one or more of them may be nearly or quite as 

 large as the lateral teeth; there are thus often three, four (PI. 91. figs. 16, 17), 

 or even five large terminal teeth. The length of these teeth is variable but I 

 have not happened to see any as long, relatively, as in Mortensen's figure. The 

 ophicephalous pedicellariae occur in two forms, that characteristic of the genus 

 (PI. 91, fig. 14) and one which intergrades with the tridentate (PI. 91, fig. 15). 



