204 
CRUSTACEA. 
they are chiefly distinguished by the want of distinct thoracic 
segments, and that these two orders are co-ordinate offshoots 
from a common stem. He replies to Dr. A. Dohrn’s objections 
(Jen. Z. Nat. vi. p. 4) to the terminology and terms chorion 
and larval skin,^^ and gives a sketch of a deformed forked 
caudal spine of Lirnulus, 
E. VAN Benedbn thinks that the knowledge of the development of 
Lhnulus proves its nearer affinity to the Arachnida (especially to the Scot- 
pimiidcB) than to the Crustacea^ and that with it the Trilohites should he 
removed from the latter to the former class. 0. R. Ent. Belg. Oct. 1871, and 
J. Zool. i. 1872, pp. 41-44 j an abstract also in Ann. N. H. (4) x. pp. 98 & 99. 
Prof. Owen identifies the caudal spine of Lwudus with the abdomen of the 
other Ck'ustaceUf Nature, Jan. 17, 1872. 
II. Woodward urges the affinity of Limulus to the Trilohites, stating, on 
Prof. Owen’s authority, that it possesses two pairs of appendages, receiving 
their nerves from the supra-cesophageal ganglion. J. G. Soc. 1871, and Q. 
J. Micr. Soc. (2) xii. pp. 169 & 160 j abstr. Ann. N. H. (4) ix. p. 406. 
CIRRIPEDIA. 
Balanidaj. 
Balanus porcatus (Dac.), crenatus (Brug.), and hameri (Ascan.) subfossil 
at the mouth of the river Jenisei, F. Schmidt, M6m. P^tersb. xviii. 1, p. C8. 
Corovmla diadema (Lam.) ?, or, perhaps, a similar but distinct species from 
Megaptera versabiHs, N.W. America: W. H. Dali, P. Cal. Ac., 1872 (p. 2). 
Crgptolepas, g. n. Scuta and terga both present, minute j valves six, ex- 
ternally produced below the surface of the whale’s skin into thin radiating 
laminae, with their planes perpendicular to the vertical axis of the animal, 
and bifurcating and enlarged towards their distal edges. C, rhachianectis, 
sp. n., sessile on Bhachianectes glaucus (Cope), id. ibid, 
LEPADIDiE. 
Ornitholepas, g. n. Stalk very short j valves absent or (in smaller speci- 
mens) four in number; carinae 0-6; thorax in front with expanded and 
jointed edges, forming a tube; cirri very short; no penis; a semilunar 
labrum and two angularly bent mandibles. O. australis, sp. n., fr’om feathers 
of the belly of Briojinm cinereus. The tube formed by the thorax may bo an 
adaptation ibr retaining water for some time ; and the shortness of the cirri 
may prevent them from drying too soon when the animal is lifted by the bird 
from the water. Targioni-Tozzetti, Bull. Ent. Ital. iv. (pp. 1-13) pi. 1. 
Otion stimpsoni, sp. n., Dali, 1. c. (p. 3), sessile on Coronula infesting Mega- 
ptera versabilis, but never on the surface of the whale itself. 
Prosopistoma (Latr.) [see Zool. Rec. viii, p. 406,], formerly placed among 
the Crustaceans, and proved by E. Joly to be the larva of an insect, pro- 
bably of the family Ephemeridce, is provided with numerous tracheae, ‘^but 
probably undergoes a metamorphosis in the larval state. M6m. Soc. Cherb. 
xvi. pp. 3-8, Ann. Sc. Nat. (6) xv., and C. R. Ixxiv. p. 1413. • 
