542 THE ANIMAL KINGDOM. 



Urinary organs in Amphipoda, Spencer, Q. J. M. xxv. 1885 ; in Stomatopoda, 

 Claus, ' Circulation in Stomatopodaj Arb. Zool. Inst. Wien, v. 1884, p. 12. 



Sexual organs of $ Cladocera, Weismann, Z. W. Z. xxvii. 1876; xxviii. 1877; 

 <, &c., xxxiii. 1880 (cf. ' Rechtfertigung,' xxx. 1878); of Ostracoda, F. Miiller, Zeit- 

 schrift f. Ges. Natw. (Giebel) 53, 1880; of Cytheridae(Ostracoda\ W. Mttller, A. N. 

 50. (i), 1884; of Oniscidae (Isopoda\ Friedrich, Zeitschrift f. Ges. Natw. (Giebel), 

 56, 1883; of $ Decapoda, Brocchi, A. Sc. N. (6), ii. 1875. 



Hermaphroditism in Cymothoidae, Mayer, Mitth. Zool. Stat. Naples, i. 1879, p. 

 165 ; cf. Nebeski, Beitrage, &c. Arb. Zool. Inst. Wien, iii. 1881, p. 24. 



Parthenogenesis in Apus, &c., von Siebold, ' Beitrage zur Parthenogenesis der 

 Arthropoden,' Leipzig, 1871; in Cladocera, Weismann, opp. citt. supra in Ostracoda, 

 Weismann, Z. A. iii. 1880, and F. Miiller, op. cit. supra. 



Changes of colour in adaptation to surroundings, Matzdorff, on Idotea tricuspidata, 

 J. Z.xvi. 1883; Weber, Isopoda Trichoniscida, A. M. A. xix. 1881, p. 591 ; cf. Seid- 

 litz, 'Beitrage zur Descendenz-Theorie,' Leipzig, 1876, pt. i; in Nika edulis, Jour- 

 dain, C. R. 87. 1878. 



Sexual colours of Daphnidae, Weismann, Z. W. Z. xxx. (Suppl.), 1878. 



Parasitism, cf. Kossmann, Z. A. v. 1882, p. 60. 



Sexual (male) Polymorphism-, in Amphipoda Chilton, (5), xvi. 1885; cf. Nor- 

 man, on Eryontidae, A. N. H. (5), iv. 1879. Influence of surrounding media on shape, 

 Schmankewitsch, Z. W. Z. xxix. 1877 ; cf. Brauer, Z. A. ix. 1886. 



Stridulating Crustacea, Wood-Mason, Nature, xviii. 1878; Neptunus vocans, 

 Milne Edwards, Bull. Soc. Philomath, Paris, 1878; Palinurus, T. J. Parker, P. Z. S. 

 1876. 



PYCNOGONIDAE. 

 (Pantopoda^) 



Marine Arthropoda with a body composed of a cephalothorax, 

 three free thoracic somites, and a rudimentary abdomen. The cephalo- 

 thorax consists of a tubular proboscis with a terminal mouth, a prae- 

 oral, two post-oral head somites, and one coalesced thoracic somite. It 

 bears four pairs of appendages, three of which belong to the head, viz. 

 a pair of 2-3 jointed prae-oral mandibles often terminated by a chela, 

 a pair of slender palpi, of ovigerous legs usually ten-jointed, and the first 

 pair of thoracic limbs which, like the other three pairs, are eight-jointed 

 and borne upon processes of the somite. The limbs have a terminal 

 and often two accessory claws. The mandibles may be absent, or the 

 palpi, or both, and the ovigerous limbs may be present only in the male, but 

 there is some variety even among specimens of the same genus. The 

 abdomen is rarely segmented and is connected to the thorax by a joint. 

 It bears the anus terminally. The integument contains numerous glands. 

 The supra-oesophageal ganglion innervates the mandibles and eyes, which 

 are placed dorsally on a tubercle of the cephalothorax. The infra-oeso- 

 phageal (=ist thoracic) ganglion innervates the palpi and ovigerous legs, 



