BULLETIN: MUSEUM OF COMPARATIVE ZOÜLOGY. 
N. radicula Lin. 
Naut. radicula Lin., 1758, Syst. Nature, ed. X. p. 711. 
Nod. radicula »'Onn., 1826, Tab. Méth., An. Sc. Nat., VIL p. 252, Mod. 1 (N. solute 
Reuss proxima). 
Nod. radicula Go&s, 1882, Ret. Rhizop. Caribb. Sea, Sv. Vet. Ak. Hdl., XIX. 4, p. 10, 
PL I. Figs. 1, 2 2. 
Nod. radicula BR., 1884, Chall. Rep., IX. p. 495, Pl. LXI. Figs. 28-31 (glandulini- 
Jormis). 
Owing to its great variability in its ovoid-cylindric shape, in its either slender 
or stout growth, in the degree of constriction of the sutures, and in the relative 
length of the segments, it will be nearly impossible to trace a distinct boundary 
line between N. radicula and N. lavigata on one side, and N. soluta REUSS 
on the other. Such forms as Gland. rotundata BORNEM., Gland. mutabilis 
(partially) Reuss are intermediate forms between JN. radicula and levigata ; 
and N. radicula b'ORR. (Mod, 1), with deep sutural constrictions and globular 
segments, is not distinguishable from N. soluta and N. Geimitzi Reuss, which 
can with difficulty be distinguished from N. glabra DORB， In his valuable 
paper on Nodosarie Terziarie del Piemonte, 1894, Bull. Soc. Geol. Ital., XII. 
(1893), fasc. 4, Rev. E. Dervieux has pointed out five varieties of this species. 
Naut. radicula Montaau, Test. Brit., 1803, was by English rhizopodologists 
once suspected to represent a Clavulina, but in Chall. Rep., IX., Brady has 
identified it with JV. radicula. About fifty different denominations have been 
bestowed on this form by authors. 
Pacific. 1201 fathoms ; rare ; slender form. 
Caribbean Sea. 120 fathoms; rare ; stout. 
N. comata Barson. 
Nautilus comatus Barson, 1791, Conchyl. Seesandes, Pl. I. Fig. 2, a-d. 
Nod. (Glandulina) glans »'Onn., 1826, Tab. Méth., An. Sc. Nat., VII. p. 252, No. 2, 
Mod. 51. 
? Nod. radicula var. Raphanus Gots, 1882, Ret. Rhizop. Caribb. Sea, Sv. Vet. Ak. 
Hdl., XIX. 4, Pl. I. Figs. 9, 10 (extenuated form). 
Nod. comata Br., 1884, Chall. Rep., IX. p. 509, Pl. LXIV. Fig. 1-5 (stout forms). 
This handsome species has not been met with by the“ Albatross,“ but it 
occurs sparingly in the Caribbean Sea at moderate depths. Small and exten- 
uated samples merge into N. scalaris BATSCH. 
Caribbean Sea. 300-400 fathoms (Go&s). 
ALLIED Form:— 
N. scalaris Barson. 
Nautilus scalaris Barson, 1791, Conchyl. Seesandes, Pl. II. Fig. 4. 
Nod. radicula var. scalaris Gos, 1882, Ret. Rhizop. Caribb. Sea, Sv. Vet. Ak. 
Hdl., XIX. 4, p. 21, Pl. I. Fig. 8. 
