608 Mr. Black wall's Descriptions of new Species of Spiders. 



Gen. Ergatis. 



Oculi subsequales, in seriebus 2 transversis in antica cephalo- thoracis parte 

 positi; seriei utriusque intermedii quadram referentes, laterales fer^ con- 

 tigui in tuberculis obliqufe positi. Maxillae mediocres, labium versus 

 declinatee, basi convexee, apice rotundatae, intils plus quam ext^s abrupt^ 

 curvatse. Labium subtriangulare. Pedes breves, mediocres ; pari Imo 

 longissimo, dein 2do, 3tio brevissimo. Tarsi triunguiculati ; unguibus 2 

 superioribus curvatis pectinatis, inferiore prope basin inflexo. 



Ergatis henigna. (Theridion henignum, Walck. Hist. Nat. des Aran. livr. v. 

 pi. 8. fig. 1. Drassus parvulus, Blackw. Research, in Zool. p. 337- Dic- 

 tynna henigna, Koch, Die Arachniden, b. iii. p. 27. tab. 83. fig. 184 — 5.) 



Ergatis latens. (Dictynna latens, Koch, Die Arachn. b. iii. p. 29. tab. 83. 

 fig. 186.) 



Ergatis viridissima. {Drassus viridissimus, Walck. Hist. Nat. des Insect. Apt. 

 t. 1. p. 631.) 



In addition to the above-named species, it is probable that the Drassus 

 Jiavescens of Kuminer might be included in the genus Ergatis, as it appears, 

 from the description given of it by M. Walckenaer (Histoire Naturelle des In- 

 sectes Aptdres, tome i. p. 632), to have a close relation of affinity with Ergatis 

 viridissima ; but it would be precipitate to place it among the Cinijlonidoe 

 before it has been proved to possess the essential characters of that family. 



When my attention was first directed to Ergatis benigna, in the autumn 

 of 1832, I supposed it to be new to arachnologists, and described it in the 

 London and Edinburgh Philosophical Magazine, vol. iii. p. 437 — 8, under the 

 appellation of Clubiona parvula. Soon after, having had an opportunity of 

 comparing this spider with specimens of Ergatis viridissima received from 

 the continent, I transferred it to the genus Drassus, with the Phytophilce, to 

 which genus it appeared to be allied (Researches in Zoology, p. 337). At 

 this period I was not aware of its specific identity with the Theridion benignum 

 of M. Walckenaer, and I am quite unable to comprehend why so accomplished 

 and discriminating an observer should still persist in separating it from the 

 forms with which it is most intimately connected by its organization and 

 oeconomy. 



