2. SPHERILLONIN/E. 



My researches in the terrestrial Isopods of late years, 

 during which time I have had occasion to examine a large 

 quantity of forms, so that the numher of the species at 

 present known can be estimated to near one thousand, do but 

 confirm my arrangement in having only 4 well distinguished 

 families*). The 3 families, Ligiidce, TyUdidce, Sysiiastidm, 

 between which no transition form is found, are nearest allied 

 with the maritime Isopods, chiefly with Idothea^*). 



I can not agree with Mr. Sars***) who divides the Li- 

 giidce in two families, Ligiidce and Trichoniscidce; the cha- 

 racters with which he distinguishes the Trichoniscidce are not 

 satisfactory, the genus Titanethes, and other genera, connect. 



The characters given by me for the 3 families are at 

 this time intactable; only with Syspastidce the following 

 character must be altered: » Antenna? interiores desunt« to 

 »Antennul9e 2-articulata3, rudimentaria?, occultae«, after 

 that Mr. Hilgendorf****) has demonstrated their pre- 



*) G. Budde-Lund: Crustacea Jsopoda Terrestria. Hauniae 1885. 

 **) If Mr. G. 0. Sars is right in his systematic arrangement in 

 his excellent work „An account of the Crustacea of Norway". 

 Bergen 1859. II, p. 3 it will be probable that the Tylididcc 

 and Syspastidce must be placed as terrestrial forms of „ Valvi- 

 fera". 

 ***) G. 0. Sars, 1. c. p. 159. 

 ****) F. Hilgendorf: Die inneren Fiihler der Oniscidengattung Sy- 

 spastus. (Situ. Ber. naturf. Fr. 1891, p. 181). 



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