532 PYCNOGONIDA chap. 



about four rows of teeth ; five pairs of legs, destitute of accessory 

 claws ; genital apertures on all the legs (Bouvier). 



Decolopoda australis, Eights ^ (1834), a remarkable form from 

 the South Shetlands, recently re-discovered by the Scotia expedi- 

 tion. The animal is large, seven inches or more in total span, 

 in colour scarlet ; it was found in aliundance in shallow water 

 and cast upon the shore. The body is greatly condensed, the 

 proboscis is " clavate, arcuated downwards," and beset with 

 small spines. A second Antarctic species, D. antarctica, has been 

 described by Bouvier. The presence of a fifth pair of legs 

 distinguishes Decolopoda from all known I'ycnogons, except 

 Pentanymphon. Stebbing would ally Decolopoda with, or even 

 include it in, the Nymphonidae ; but the presence of a second 

 joint in the chelophoral scape, the number of joints in, and the 

 armature on, the ovigerous legs, and the deflexed proboscis, are 

 all characters either acjreeintr with or tending towards those of 

 the Eurycididae ; while the Colossendeidae would be very like 

 Decolopoda were it not for the complete suppression of the 

 chelophores. It seems convenient to constitute a new family 

 for tliis remarkable form. 



Fam. 2. Colossendeidae (Pasithoidae, Sars). — Appendage I. 

 absent in adult ; appendage II. very long, 10-jointed; appendage 

 III. 10-jointed, clawed, with many rows of teeth ; auxiliary claws 

 absent ; segments of trunk fused ; proboscis very large, somewhat 

 mobile ; genital apertures, in at least some cases, on all the legs. 



Fasithoe, Goodsir (1842), which Sars assumes as the type of the 

 family, is here relegated to Ammoiliea? Colossendeis, Jarszynsky 

 (1870) {AnomorhyncMis, Miers (1881), Rhopalorliynchus, Wood- 

 Mason (1873)), remains as the only genus commonly accepted : 

 large, more or less slender short - necked forms ; world-wide, 

 principally Arctic, Antarctic, and deep-sea ; about twenty-five 

 species.^ The largest species, C. gigas, Hoek, from great depths 



Exped. 1899 ; Mobius, Fauna Arctica, 1901, Valdivia Exped. 1902 ; Cole, Karri- 

 man Alaska Exped. 1904 ; Hodgson, Discovery Exped. 1907 ; Bouvier, Exp. 

 Antarct. Fr. 1907. 



1 Boston Journ. Nat. Hist, i., 1834, p. 203 ; Cf. Hodgson, Pr. 21. Phys. Sue. 

 Edinburgh, xvi., 1905, p. 35; Zool. Anz. xxv., 1905, p. 254; Discovery Exp., 

 " Pycnogonida," 1907 ; Bouvier, Exp. Antarct. Fr. 1907. 



2 See pp. 535, 541. Cf. Dohrn {t. cit.), p. 228. 



^ The first known species was described as Phoxichilus proboscideus, Sabine, 

 from the shores of the North Georgian Islands (1821). 



