■44 ON A NEW BRITISH TERRESTRIAL ISOPOD. 



EXPLANATION OF PLATE 7. 



Fig". 1. Feoaale of Trichonhcus stehhimji. 



Figs. 2, 3. Antennula of male, wltli portion of last joint more 



highly magnified , 

 Fig. 4. Antenna of male. 



Fig. 5. One of the first pair of pleopoda of male. 

 Fig. G. One of the second pair of pleopoda of male. 

 Fig. 7. Seventh paraeopod of male. 

 Fig. 8. Mandibles. 

 Fig. 9, Last segment of metasome with uropods. 



Postscript. — Since the above was read before the Society, I have found 

 this species occurring in widely separated parts of the Clyde f'aunal area, e.y.^ 

 in several other localities around Glasgow ; at Hawkhead in Renfrewshire ; 

 at Ayr, and at Uddingston in Lanarkshire. In the last-named place, I found 

 it in considerable numbers in the greenhouse of my friend, Mr. Peter Ewing, 

 F.L.S., who informed me that he has observed the species there for the past 

 twenty years, and suggests that it may have been introduced into his green- 

 house nlong with the roots of Sphagnum taken from some of the Scottish hills. 



Whilst engaged in investigating the distribution of T. steNnvgi, I met with 

 another species in a greenhouse in Springburn Park, Glasgow, which offers 

 some points of resemblance to the above-named species, and which I have 

 described in ' The Annals of Scottish Natural History' (April 1907, pp. 85- 

 88, pi. 3) under the name of Trichoniscus spinosus. The dorsal face, instead 

 of being tuberculate, is closely covered with small spines directed backwards ; 

 the flagellum of each antenna is composed of three articulations, and the last 

 joint of the last pair of legs in both sexes has on the outer edge three or four 

 short but fairly promment spines. It resembles T. steUnngi " in the general 

 form of the body, in the type of coloration, in the structure of the first pair 

 of pleopoda of the male, and in the shape of the last segment of the metasome. 

 The telson, however, in T. spinosus is more obtusely rounded at the tip than 

 in the above-named species, and in this respect connects 2\ stehlnngi with the 

 other British species of Trichoiiiscus, where the tip of the last segment of the 

 metasome is truncate. Ag;iin, the last joint of the inner ramus of the first 

 pair of pleopoda of the male is slightly longer and comparatively more 

 slender than in T. stelhingi, while the colour arrangement on the dorsal face 

 presents a more definite pattern. The antennse, legs, and uropoda, which in 

 T. spinosus are coloured, are in T. stehUngi generally devoid of pigment." 



A. Patience. 



29th April, 1907. 



