REPORT ON THE ANNELIDA. 
155 
Leanira hystricis, Ehlers (PL XXIII. fig. 9). 
Leanira hystrids, Ehlers, Ann. and Mag. Nat. Hist., ser. 4, vol. xiii. p. 292, et infra. 
Leanira hystrids, MTntosh, Trans. Zool. Soc. Lend., vol. ix. p. 408. 
Habitat . — Two fragmentary examples were dredged at Station 73 (to the west of the 
Azores), June 30, 1873 ; lat. 38° 30' N., long. 31° 14' W.; depth, 1000 fathoms; bottom 
temperature 39°'4, surface temperature 69°’0 ; sea-bottom, Pteropod ooze. 
A third fragment without a head occurred at Station 76 (off the Azores), July 3, 
1873 ; lat. 38° 11' N., long. 27° 9' W.; depth, 900 fathoms; bottom temperature 40°'0, 
surface temperature 70°'0 ; sea-bottom, Pteropod ooze. 
The same form was found at Station 7 in the “ Knight Errant,” August 12, 1880; lat. 
59° 37' N., long. 7° 19' W., in 530 fathoms. 
These specimens are larger than any procured in the “ Porcupine,” off the south-west 
coast of Ireland, and examined by Ehlers or myself. Ehlers refers to one (probably his 
largest) 19 mm. in length and having a breadth of 2 mm., including the bristles, whereas 
the longer example from the first Station was 42 mm. in length, and with the bristles had 
a diameter of 3 '5 mm. 
The publication of a complete description with figures by Ehlers,^ since my former 
note,^ enables a more minute comparison to be instituted. The larger examples procured 
in the Challenger also show certain points more clearly than in any previous specimen. 
The figure of the head, tentacle, and upper tentacular cirri given by Ehlers deviate 
considerably from my former description and the parts in the examples just named. The 
processes (tentacle, &c.) are too large, and the distal undulations too pronounced. The 
tentacle does not taper sufficiently at the distal end. The anterior scales are also some- 
what less than in Ehlers’ figure. Both the first and second scales are small and rounded. 
Ehlers observes that the species approaches the Leanira quatrefagesi of Kinberg,^ from 
the Atlantic, off the Rio de la Plata. A more minute investigation of Kinberg’s specimen, 
indeed, is necessary before all doubts as to the specific separation are removed. They 
closely agree in regard to the structure of the scales, bristles, and general condition of the 
head and its processes, and seem to differ chiefly in regard to the structure of the feet, 
and in the absence of eyes in Leanira hystricis, a pair being present in the other form. 
In transverse section the specimen from Station 73 quite differs from the other in 
regard to the nerve-area, which is elongated and flattened, the oblique muscles being 
attached to the outer angles only. The cuticle is comparatively thick veutrally. The 
ventral longitudinal muscle is flattened and the dorsal fold thin. The nerve-cords are 
flattened. There is a distinct elevation or thickeniug on each side of the polar ridge of 
1 Zeitschr.f. wiss. Zool., Bd. xxv. p. 35, Taf. ii. figs. 5-11, 1875. 
2 Trans. Zool. Soc. Lond., vol. ix. pt. vii. p. 408, pi. Ixxiii. figs. 6-8. 
^ Freg. Engen. Eesa, &c., p. 30, Taf. ix. fig. 42, &c. 
