138 



chalus. Of the two latter authors, the claim of 

 priority is with Mr. Curtis, and his name should 

 be retained, as that of Dr. Leach cannot be sus- 

 tained. The species of Cybister are more numerous 

 than those of true Dyticus ; they are generally 

 robust, and are the most powerful insects of the 

 Aquatic Adephaga; the destruction they cause 

 among the tropical fishes, as described to me by 

 Indian travellers, is wonderful ; they are reported 

 to destroy ten times the quantity they can possibly 

 consume, and may justly be considered amongst 

 the most ravenous of insects. 



Sp. 3. Marginalis. — Of this species of Dyticus 

 I have seen three remarkable monstrosities ; the 

 first was deprived of its anterior tibiae and tarsi, 

 and had only the rudiments of legs ; a second spe- 

 cimen had three anterior right legs. The third mon- 

 strosity, is an Hermaphrodite, which I captured at 

 Netley in Shropshire ; it has lately been figured 

 by Mr. Westwood, and will probably be published 

 in a future number of the Entomological Transac- 

 tions. 



Sp. 8. Atratus. — Probably a Cybister. It was 

 captured by Billiardiere, at some of the islands of 

 the Pacific Ocean. 



Sp. 9- Costalis. — This species is sometimes dread- 



