CIRRIPEDIA, XIPHOSURA. Grust, 37 
Peltogastrida*:. 
Sacculina carcini. Its sucking appendages, “ sai’corhizaB are ramified 
delicate tubes with milk-white contents, which form a very complex 
network round the digestive tube, and extend to the liver, the genital 
gland, and even the sternal muscles and extremities of the limbs of 
their hosts, but never touch the heart, gills, or central nervous system, 
so the crab apparently retains its general health. The Sacculina is 
itself infested by a species of Saccharomyces, which destroys it. S. 
Jourdain, C. R. xcii. pp. 1352-1354; abstract in J. R. Micr. Soc. (2) i. 
p. 601. 
Sylonhymenodorai, sp. n., G. O. Sars, Arch. Math. Naturvid. 1881, p. 469, 
North Sea, 1862 fath., under the last cephalothoracic segment of Hyme- 
nodora glacialis. 
XIPHOSURA. 
E. Ray Lankestei{, from a comparison of the nervous system, the 
skeleton of the abdominal region, the alimentary tract, &c., now comes to 
the conclusion that Limulus agrees more with the Scorpions than with the 
Crustacea^ and ho proposes a new order of Arachnida^ to be called Ilccmo- 
hranchia^ for its reception. Q. J. Micr. Sci. xxi. pp. 504-548, 609-649, 
with 2 pis. ; abstract in J. R. Micr. Soc. (2) ii. pp. 40 & 41. 
Limulus uses its caudal spine for turning itself round when fallen on 
its back ; J. de Bellesme, Ann. Sci. Nat. xi. No. 7, 5 pp. [This has long 
ago be6n observed by the Recorder and others.] 
Trilobitj]. 
C. D. Walcott’s researches on the organisation of the Trilobites may 
be here mentioned ; according to them, the ventral membrane was thin 
and delicate, strengthened in each segment by a transverse arch, to which 
the appendages were attached ; there was a series of 6-7-jointed ambu- 
latory legs extending from the cephalic shield beneath the thorax and 
pygidium to the posterior segment of the latter. An epipodite and a 
branchia were attached to the basal joint. The appendages beneath the 
pygidium did not essentially differ from those of the thoracic segment. 
The eggs of the Trilobites, which are found beneath the dorsal shield, 
are also noticed. The author places the Trilobites in a distinct class, 
Poccilopoda, which includes also Limulus and the Eurypteridoi, and which 
has its place after the Crustacea and before Arachnida. Bull. Mus. 
C. Z. viii. pp. 191-224 with 6 plates ; abstract in J. R. Micr. Soc. (2) i. 
pp. 736 & 737, and in Arch. Z. exp^r. ix. p. xlvi.-xlviii. Some objections 
by “ J. D. D.” in Am. J. Sci. (3) xxii. p. 79. 
H. Milne-Edwards gives an abstract of Walcott’s paper in Ann. Sci. 
Nat. (6) xii. art. 3, 33 pp., coming to the conclusion that it would be very 
artificial to unite the Trilobites with Limulus in the same higher group ; 
he thinks, on the contrary, that Walcott’s observations confirm the 
position of the Trilobites between Isopoda and Phyllopoda, which he 
assigned them many years ago. 
