52 me. e. j. miees ok the id0teidj3. 



Idotea ungulata. 



Oniscus ungulatus, Pallas, Spicil.Zool. ix. p. 62, pi. iv. fig. 11 (1772). 



Idotea ungulata. Lam. Hist. Anim, sans Vert. v. p. 160 (1818). 



Idotea Lalandii, M.-Edwards, Hist. Nat. Crust, iii. p. 132, pi. xxxi. fig. 7 

 (1840); Krauss, Sudafrik. Crust, p. 61 (1843). 



Idotea affinis, M.-Edw. Hist. Nat. Cr. iii. p. 133 (1840) ; Krauss, Sud- 

 afrik. Crust, p. 61 (1843); White, List Cr. Brit.Mus. p. 95 (184/); 

 Heller, Cr. in Reise der Novara, p. 130 (1865) ; Miers, Catalogue of 

 New-Zealand Crustacea, p. 93 (1876); Thomson, Trans. New-Zeal. 

 Inst. xi. p. 232 (1879). 



Idotea Edwardsii, Guerin-Meneville, Icon. Cr. R. Anim., texte Cr. p. 33 

 (1829-44). 



Idotea nitida. Heller, Verhandl. zool.-hot. Vereins lVien,-p. 497 (1861); 

 id. Cr. in Reise der Novara, p. 131, pi. xii. fig. 1 (1865). 



Body obloDg, moderately conyes, aud nearly smooth. Head 

 with tlie frontal margin very slightly concave, but with a slight 

 depression in the middle ; antero-lateral angles usually but little 

 prominent, smooth above, or with faint indications of an im- 

 pressed curved line near the posterior margin. Segments of the 

 thorax smooth ; the first the shortest, its antero-lateral processes 

 obtuse ; the postero-lateral angles of the first to third segments 

 rounded, of the fourth to seventh segments rectangular or acute. 

 Postabdomen somewhat depressed towards its distal extremity, 

 smooth, with lateral sutures indicative of two coalescent seg- 

 ments; terminal segment with the lateral margins straight to 

 within a short distance of the postero-lateral angles, which are 

 either obtuse or acute; distal end emargiuate. Eyes small, black. 

 Antennules not reaching to the distal end of the penultimate 

 joint of the peduncle of the antennae. Antennae when retracted 

 not reaching to the posterior margin of the fourth thoracic seg- 

 ment, and often much shorter ; last two joints of the peduncle 

 short and subequal ; flagellum longer than the peduncle, with 

 12 to 28 joints. Epimera rather narrow, in the second and third 

 thoracic segments scarcely occupying more than half the length 

 of the lateral margins, in the fourth to seventh segments occupy- 

 ing their whole length ; only the last two epimera on each side 

 have their postero-lateral angles acute. The legs are robust; 

 the fourth to seventh pairs of legs have their posterior and outer 

 angles of the merus aud ischium produced, and in adult examples 

 spiniform. The posterior plates of the opercular valves are 

 buadrate and nearly square. The length of the largest example 



