The Scottish Naturalist. 



3°3 



- - -. The test. mars, of th. much wider than in the 

 other species, the mars, at fr. and ba. being together 

 as wide as the space between them. E. with numer- 

 ous fine longi. yel. lines. 12 1. S.I. 



Acilius. 



Very wide and flat ; sides very round. Closely and 

 finely punc. Brown b. An., pal., some marks on 

 h., mars, of th., a line on disc of th. , mar. of e., 

 u.-s. of th., fr. 4 legs (exc. part of up. side of ant. 

 legs), r.-m. of e., some spots on u.-s. of each seg. 

 (exc. 1st) of h.-b., and ap. part of hi. fern., test. 

 E. of ? with 2 hairy fov. on th., and 4 on e. "]% 1. 

 F S T * 



I - . ■ . X* • • • • • * 



Very like prec. Narrower. On u. -s. all segs of h. -b. , 

 marked (more plentifully) with test. Hi. fern. test. 

 In ? no hairy fov. on th. ; 3rd fov. on e. narrower. 

 7 1. B. N ' . 



lapponicui 



sulcatus 



canaliculatu- 



Hydaticus. 



1. Not very wide. Widest about mid. of e. U.-s. dusky 



or b. Mid. tar. of 6 with 3 strongly dil. js. Very 

 minutely and closely punc, Avith dist. rows of larger 

 puncs. ... ... 



Wide. Widest behind mid. of e. U.-s. test. Mid. 

 tar. of 6 little dil. Finely and spar. punc. E. with 

 obsc. rows of larger puncs. H. and th. test. ; some 

 marks on h., ba. of h., and ba. and fr. of th., b. 

 E. test., very thickly sprinkled with b., exc. on 

 mars. Legs, an., and pal., test. 7 1. E.*- 



2. B. Fr. of h. , fr. and side mars, of th. , mar. of e. , pal. , 



an. , and fr. legs, test. 6^ L. E. . 

 Very like prec. Less closely and evenly punc. Mars, 

 of th. more widely test. A tr. yel; fasc. near ba. of 

 e. 6 1. E. 



cuiereus 



semmiger 



transversalis 



Fifth Family— GY RINID^E. (2 genera. ) 



Shining. Last seg. of h.-b. rounded at ap., and flat. 



[Legs test. ] . 

 Dull. Pub. Last seg. of h.-b. el., pointed at ap. 



[Legs test.] ...... 



Gyrinus. 



1. U.-s. of h.-b. test, or pale brown 



- - - b. R. -m. of th. and e. , and the claws, test, or r. 

 [Shining b., bl., or gr. Breast and ap. of h.-b. often 

 reddish. E. with about 11 longi. rows of puncs.] . 



- (exc. legs) wholly b. Claws b. (ant. only at ba.) 



Otherwise as above. .... 



Gyrinus 

 Orechtochilus 



3 

 6 



