236 Transactions of the Society. 



has spurs twice as long as those two figured, and similar to those 

 figured by Milne. The teeth are 4 + 1 in each jaw. Length, 

 250 yLt to 300 yu- wheu feeding. 



Brazilian examples are the largest yet seen, measuring about 

 500 fi in length when feeding. The jaws are 50//, in length, 

 spurs SO fM. Each spur is slightly constricted in mid-length, and 

 they are close together. 



Habitat. — Santa Anna, Tuichi Valley, Bolivia; summit of 

 Corcovada mountain, Eio de Janeiro. 



Pleuretra hrycei Weber. 



Two very distinct varieties of this protean species are figured 

 in my Notes on Bolivian N'atural History (^4)- Two others, 

 related to one another, found in Eio are here figured. 



Variety (Plate IX, fig. 7). — Spines on anterior dorsal border 

 of trunk very widely separated by straight interspace. Lateral 

 spines of second trunk segment two to four on each side. Main 

 dorsal row of normal ten spines. On fourth central two spines 

 widely separated. On pre-anal segment two, four, or six small 

 spines. 



On the first trunk segment there are rudiments of delicate 

 lateral processes, which are only known otherwise in a variety 

 from La Paz (see i2Jf,, p. 22, fig. 7). 



Variety (fig. 8).- — Anterior spines widely separated, as in the^ 

 previous variety. No lateral processes on first trunk segment. 

 Lateral spines on second trunk segment two a-side. Main row, 

 ten spines. On fourth central, six spines. On pre-anal, two spines. 



Habitat. — First variety, the Zoological Gardens, Eio de Janeiro ; 

 second variety, Sylvestre, Eio. 



EXPLANATION OF PLATE X. 



Fig. 10. — Callidina multisphiosa, variety. 



,, 11. Ditto. Another variety. 



,, 12. Ditto. Another variety. 



,, 13. Ditto. Another variety. 



,, lia. — Oecistcs jpectinifer ?,T^. n. Dorsal view. 



,, 146. Ditto. Lateral view. 



,, 14c. Ditto. Ventral view of head. 



,, 14^. Ditto. The " comb " of another example. 



„ 14 f. Ditto. Teeth. 



,, 15. — Polychastus collinsi. Variety with four spines on foot.. 



,, 16a. — Rattulus braziliensis sp. n. 



,, 166. Ditto. Another view. 



,, 17a. — DiurcUa voluLa sp. n. Lateral view. 



,, 17 6. Ditto. Three-quarter ventral view. 



,, 17 c. Ditto. Ventral view. 



,, lid. Ditto. Diagrammatic section. 



