1730 



THE VOYAGE OF H.M.S. CHALLENGER. 



Commensal, one that feeds with, not like a parasite at the 



expense of, another, 392, 579. 

 Commissures (commissura, a connection, a band), the longi- 

 tudinal fibres connecting the various ganglia. In 

 Gammarus neglectus Sars describes a cerebral ganglion, 

 seven thoracic and four abdominal ganglia, with a pair 

 of separate commissures between each and its successor. 

 The last three are considerably longer than those in 

 front. From all of them nerves are given off as well as 

 from the ganglia. In their structure Sars distinguishes 

 an outer membrane and an inner granular content, 

 composed of numerous ganglionic cells. In the Caprel- 

 lidae the abdominal commissures are naturally reduced to 

 the vanishing point. 133, 489, 1646. 

 Complexly chelate or subchelate. " By this term [complexly] 

 I mean, whenever the chelate character depends upon 

 other joints than the propodos " (Brit. Mus. Catal. 

 Amph. Crust., p. 262). For the German equivalents, 

 see p. 597. 

 Condylipoda, condylipodes, condylopa, condylopes, condylopoda 

 {k6v$v\os, knuckle or knob of a joint, irovs, a foot), 

 "pattes noueuses," 72, 125. 

 Condylopia, 88. 



Connective-tissue. " Immediately beneath the epithelial layer 

 follows a tissue, disposed in bands or sheets, which 

 extend to the subjacent parts, invest them, and connect 

 one with another. Hence this is called connective tissue" 

 (Huxley, The Crayfish, p. 178). Mayer describes it as a 

 thin layer, not continuous but with lacunee, under the 

 whole epidermis in the head and body, present also in 

 the antenna? and legs, except at their extreme points, 

 throwing out attachments to the liver and stomach and 

 heart, dividing the body into dorsal and ventral com- 

 partments, sheathing the ganglionic chain, and by its 

 strong development in the branchiae assisting in the 

 purification of the blood, which is thus the longer exposed 

 to the influence of the surrounding water. (Die Caprel- 

 liden, p. 130). 

 Coxopodite (coxa, the hip, irois, a foot) ; the equivalents are 

 first joint, side-plate, hanehe, Basalglied, Hiiftglied, 

 Seitenplatte, erstes Coxalplatte, Coxa, Femur, Epimeron, 

 Epirueruni. It is a disputed question whether we have 

 at the base of the Amphipod leg a lateral plate which is 

 an outgrowth of the body-ring, carrying the more or less 

 obsolescent first joint of the leg soldered to it, or whether 

 the side-plate is itself a protective expansion of the first 

 joint. 149, 289, 290, 365. 

 Crochet, 48, 140. See dactylopodite. 



Crustacea (crusta, the hard surface of a body, the rind or shell, 

 "Aquatilium tegumenta plura sunt. Alia . . . integ- 

 untur . . . crustis, ut loeustre," Plin. ix, 14), 6, 17, 

 52, 62, 66, 71, 78, 79, 125, 155, 169, 479, 552, 1655. 

 See also Encycl. Brit., vol. vi. p. 333, 1878 (H. Wood- 

 ward). 

 Crustaeeology, a hybrid word used by Leach to include the 



natural history of Crustacea and Arachnides, 83. 

 Crustata. The word Crustata applied to animals appears first 

 to occur in Pliny, xi, 62, "Et cochleae dentes habent : 

 indicio est etiam a minimis earum derosa vitis. At in 

 marinis crustata et cartilaginea primores habere, item 



echinis quinos esse, unde intelligi potuerit, rniror." In 

 Faceiolati's Lexicon, the quotation, "in marinis crustata 

 et cartilaginea primores dentes habent," makes Pliny 

 assert the very thing of which he expresses himself as 

 doubtful. Facciolati gives as an explanation of the word 

 crustata, "h.e. pisces crusta, seu testa obducti." 

 Jonston, De Exanguibus aquaticis, Lib. ii. c. 1, says, 

 " Quae Crustata Pliuio, ilia Latinis aliis Crustacea, quod 

 molli crusta operta sint, Graecis naXanoiTTpaKa, eandem 

 ob causam dicuntur. Medium inter Testacea et 

 Mollusca sortita locum videntur. Nam quatenus foris 

 crusta, etsi fragili et tenui obteguntur, cum testaceis 

 conveniunt: quatenus molle carnosumque intus continent, 

 mollibus comparantur." 2, 4, 193. 



Cryptobranehes (Kpinra, I conceal, (Spayx'a, breathing- 

 organs), 96. 



Crystalline cones, Krystalkegel, cristallin, 154, 462, 481, 490, 

 495, 1638, 1652. 



Crystallites, Cristallites, little plates, concentrically striped and 

 radiated, found between the epithelium and cuticle in 

 Caprella and some of the Ganimaridas. In diluted acetic 

 acid they disappear with a lively evolution of gas. The 

 markings can sometimes be subsequently traced in the 

 cuticle (Hoek, Carcin., p. 98, 1879). 



Cuisse. See Meropodite, 93, 140, 155. 



Cupule membraneuse, 141, 543. See Calceolus. 



Cuticle (cuticula, skin, diminutive of cutis) ; the outer layer 

 of the integument, lining both the body externally, and 

 internally the alimentary canal, with the exception of 

 the midgut (Bruzelius, Mayer, Spencer), 574. According 

 to Huxley, The Crayfish, pp. 33, 196, the exoskeleton 

 or cuticle is ' ' produced by the cells which underlie it, 

 either by the exudation of a chitinous substance, which 

 subsequently hardens, from them ; or, as is more 

 probable, by the chemical metamorphosis of a superficial 

 zone of the bodies of the cells into chit in." It is this 

 exoskeleton, and not the epidermis or true skin which 

 secretes it, that is thrown off in the process of ex- 

 uviation. 



Cylinders, 480, 626. In the descriptive part of this Report the 

 expression filamentary cylinders has been frequently used 

 for the Riechzapfen or olfactory tubes, as they are gene- 

 rally supposed to be : but the single word filaments has 

 been adopted in the later descriptions, since Leydig has 

 applied the name cylinder to a different kind of appen- 

 dage. 



Cystibrancb.es, Cystibranchia (kiWis, a bladder, 0payx^< 

 breathing-organs), 95, 96, 99, 135. 



Dactia ($&kvw, I bite), 282. 



Dactylopodite (SkktuAos, a finger or toe, irovs, a foot), seventh 

 (sixth free) joint of the Amphipod leg ; the equivalents 

 are — sixth joint, seventh joint, claw, finger, nail, crochet, 

 doigt, griffe, tarse, Klaue, Endklaue, dactylos, dactylus, 

 unguis, 140, 149, 155, 290, 532. 



Dactyloptera (ScJktuAos, finger , impiv, a wing), "this name is 

 suggested for the two little wing-like plates on each pair 

 of gnathopoda " (Spence Bate on Phronima sedentaria, 

 Brit. Mus. Catal. Amph. Crust., p. 317), 1341. 



Darmcanal, 489, 562, 598. See Alimentary Canal and 

 Intestine. 



