280 Mr. A. Patience on a new 



XLV. — On a new Brituh Terrestrial Isopod (\^\\(:\\on'\^c\xs 

 linearis, sp, n.). By Alexander Patience, 



[Plate XI.] 



Family Trichoniscidae. 



Genus Trichoniscus, Brandt, 183.3. 



Trichoniscus Imearis, sp. n. (PL XI.) 



Description of species. — Body oblong linear in form, fully 

 three and a halt" times as long as broad. Dorsal face 

 moderately convex and very strongly taberculated trans- 

 versely across the segments. Ocphalon -with front obtusely 

 rounded ; lateral lobes fairly prominent and each bearing 

 one or two tubercles. Lateral parts of the segments of 

 mesosome having no obvious spicules, the lateral parts of the 

 three posterior segments recurved and acuminate. Metasome 

 occupying less than one fourth of the length of body, the 

 terminal expansion being broadly rounded at the tip and 

 carrying three small spicules. Eyes consisting apparently 

 of a single visual element imbedded in daik pigment. 

 Antennulse with the last joint about twice the length of 

 .second and having from five to seven sensory filaments. 

 Antennae about one-third the length of body, the joints of 

 ])eduncle being strongly spinulose, and the flagelluin being- 

 composed of four articulations. Left mandible with two, 

 right with one, penlcil behind the cutting part. The meral 

 joint of seventh perseopod in male is broadly expanded, 

 while the last joint is densely ciliated on the outer edge. 

 The seventh perteopod in female not observed. Liner ramus 

 of first pair of })leopoda in male biarticulate ; the terminal 

 joint about same length as first, and ending in a sharp 

 point turned slightly inwards and finely serrated on the outer 

 edge. Inner ramus of second pair biarticulate, proximal 

 joint short; the distal joint greatly produced, contracted at 

 about half its length and then produced to a fine hair-like 

 point. The tip of the outer plate reaches to about the middle 

 of distal joint of inner ramus. Uropoda with outer ramus 

 about twice the length of basal part, the inner ramus 

 being narrower and shorter. Colour of the living animal, 

 white, semipellucid, the male exhibiting; slight ramifications 

 of minium-red across the segments. No trace of pigment 



