498 SOCIÉTÉ ROYALE ZOOLOGIQUE ET MALACOLOGIQUE DE BELGIQUE. 

species of Trichoniseus have, however, been more recently discovered, … 
and as the form of the telson in both is similar to that of T. Steb- . 
bingi 1 append a rough tabulation of the three species. | 
The species of the genus Trichoniseus may be thus divided : 
Terminal expansion of the metasome truncate or emarginate. 
pusillus Braxpr, roseus Kocnu, vividus Kocn, intermedius BAGNALL, 
pygmæus G. O0. SANS: LUE. Le Ar ESSOR A 
Terminal expansion of the metasome rounded at the tip. 
linearis PATIENCE, Stebbingi PATIENCE, Spinosus PATIENCE. . . Il 
Only the three species of the second group concern us; though 
pygmæus of the one division and lénearis of the other are very 
closely allied and in a way naturally connect the two groups. 
IL. — Terminal expansion of metasome rounded at the tip. 
A. Form very linear. Eyes composed of a single visual element 
| linearis PATIENCE ('). 
B. Form oblong-ovate. Eyes normal, composed of three visual 
elements : 
a) Dorsal surface spinulose. Flagellum of antennæ 3-articu- 
late. Antennæ, legs and uropoda colored. 
| spinosus PATIENCE (2). 
aa) Dorsal surface tuberculate. Flagellum of antennæ 4-to 
7-articulate. Antennæ, legs and uropoda as a rule 
colorless..., 4. "1e 7 "Stebbings PATIENCE. 
T. spinosus has up to the present only occurred in a greenhouse 
in Springburn Public Park, Glasgow, where Mr. PATIENCE 
discovered it on February 6”, 1907. 
T. linearis, a very distinct little creature, was described from two 
females and a male taken by the present writer in a moderately cool 
greenhouse, Kew Gardens, London, December 3", 1907, in com- 
pany with Haplophthalmus danicus. 
Although T. Stebbingi was first discovered by Mr. PATIENCE in 
the open country it has only been found since in greenhouses, and 
in such habitats sems to be a not uncommon and widely distributed 
species. It apparently occurs throughout the Clyde faunal area of | 
(4) ANx. AND Mac. or NarTuRAL History, ser. 8, vol. I, March 1908, pp. 280- 
282, pl. XI. 
(2) An. or ScortisH NATURAL History, April 1907, pp. 85-88, pl. III. 
