42 , MR. ALEXANDER PATIENCE ON A 



EXPLANATION OF PLATE 6. 



Tach.^a spongillicola, sp. D. 



n. s. ^,n.s. (^ , Lines indicating natural size of female specimen seen in dorsal 

 view at top of plate, and of male specimen from wliicli some of tlie 

 appendages are figured. 



a. s., a. i. First and second antenute of female. 



VI., ma: 1., ni.vp. Mandible, first maxilla, and maxilliped of female. 



m.v.l (S ,m.v. 2 (S , mxp. (^ . First and second maxillae and maxilliped of male. 



jn-^). \,prp. 2. First and second per.ieopods of female. 



^9??. 1 cT ) P^T' ^ 6 • First gnathopod and fifth peraeopod of male. 



PL, 2)lp. 2 S , iirp. (^ . Pleon of female, with one uropod omitted: second pleopod 

 and uropod of male. 

 The mouth-organs are magnified to a higher scale than the other appendages. 



On a new British Terrestrial Isopod. By Alexander Patience. 

 (CommmiicateJ by the Rev. T. R. R. Stebbing, M.A., F.R.S., Sec.L.S.) 



(Plate 7.) 



[Read 17th January, 1907.] 



Fam. TRICHONISCID^. 

 Gen. Trichoniscus, Brandt, 1833. 



Trichoniscus stebbingi, sp. n. (Plate 7.) 



Body oblong oval in form, about two and a half times as long as it is 

 broad. It attains the greatest width about half the total length. Dorsal 

 face convex and very strongly tuberculated, the tubercles being arranged 

 transversely in rows across the segments. Cephalon with the front obtusely 

 rounded ; lateral lobes moderately produced, and armed with two small 

 spines on outer edge. Lateral parts of the segments of mesosome edged 

 "with very small spicules, which are concealed, however, in a fringe of short 

 hairs ; the lateral parts of the three posterior segments prominent, recurved, 

 and acuminate. Metasome with the terminal expansion of last segment 

 broadly and evenly rounded at the tip and armed with four triangular spines, 

 the two central being the largest. Eyes consisting of three visual elements 

 imbedded in dark pigment. Antennulffi with the last joint much longer than 

 the second and having five to seven filaments. Antennjis about one-third the 

 length of body, the flagellum being composed of from four to seven articu- 

 lations. Left mandible with two, right with one, penicil behind the cutting 



