Crustacea.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 661 



Trichoniscus thomsoni (Chilton). 



Philygria thomsoni, Chilton, Trans. N.Z. Inst., xviii, p. 159, pi. v, figs. 1-6, 

 1886. Trichoniscus thomsoni, Chilton, Trans. Linn. Soc, viii, p. 118, 

 pi. xiii, fig. 1, 1901 ; Budde-Lund, Deutsche Siid-polar Exped., 1901-3, 

 ix, p. 83, pi. iv, figs. 22-24, 1904. 



A lew specimens obtained at Auckland Islands appear to belong to this 

 species. They dif?er slightly from specimens from the main islands of New 

 Zealand in having the surface of the body somewhat rugose, and in having the 

 fifth joint of the peduncle of the antennae roughened with setose tubercles on 

 its inner side. They are, however, too closely related to be distinguished as a 

 separate species. 



Dr. Budde-Lund has pointed out that the species of Trichoniscus from New Zea- 

 land, Tierra del Fuego, and other places in southern lands belong to a section of the 

 genus which is distinguished by having the three ocelli of the compound eye sepa- 

 rated from one another, and to this section he has added a new species, T. verrucosus, 

 from the Crozet Islands. Dr. Budde-Lund has also pointed out the near relation- 

 ship between T. thomsoni and T. magellanicus, and the existence of the latter 

 species on Auckland and Campbell Islands has enabled me to confirm what he says. 

 T. thomsoni differs, however, in having the segments of the peraeon broader, the 

 lateral parts especially being greatly dilated, and, as a result, the body is less convex 

 than in T. magellanicus ; the uropoda, though closely similar, are hardly so long 

 and slender as in T. magellanicus. 



Trichoniscus magellanicus (Dana). 



Styloniscus magellanicus, Dana, U.S. Expl. Exped., xiii, Crust., p. 736, 

 pi. xlviii, figs. 7 a-g, 1853 ; Dollfus, " Mission du Cap Horn," Crust., 

 p. F92, fig. 14 a-c. Trichoniscus magellanicus, Stebbing, P.Z.S., 1900, 

 p. 566 ; Budde-Lund, Deutsche Siid-polar Exped., 1901-3, ix, ZooL, i, 

 p. 83, pi. iv, fig. 25, 1904. 



Several specimens from Auckland Island, and some also from Campbell Island, 

 must, I think, be referred to this species, which is also known from Tierra del Fuego 

 and from the Falkland Islands. 



My specimens agree very closely with the description of the species given by 

 Stebbing, the only point of difference that I can find being that the flagellum of the 

 outer antenna contains only six joints, indistinctly marked, while his specimens were 

 7-8-jointed. The species also seems very close to T. verrucosus, Budde-Lund, from 

 the Crozets, which has four to six joints of the flagellum of the antenna ; that species, 

 however, appears to have the surface more rugose than in my specimens. Probably 

 T. verrucosus will prove to be either identical with T. magellanicus or only a local 

 variety of this widely distributed subantarctic species. 



Genus Haplophthalmus, Schobl, 1860. 



Distribution. — As yet recorded only from Europe and America and New Zealand, 

 but I have also an undescribed species from Tasmania. The New Zealand species 

 differ from the generic characters in one or two points (see below). 



