﻿226 LE CONTE.— SYNOPSIS OF THE 



the posterior pair in the groups of genuine Melolonthidse varies. Why, then, may 

 not all these cases of variation, great or small, in the position of the stigmata be 

 brought together in one large group, which may be placed between the pleurosticti 

 and laparosticti, connected more closely with the former than with the latter. The 

 essential character of this large group seems to be the negation of the characters of 

 the other two ; and we would thus have the following expression of relations : 



Stigmata abdominis in segmentis ventralibus sita postice fortiter divergentia, ultima 

 conspicua ............... Laparosticti. 



Stigmata abdominis parum divergentia, variabiles, at in membrano non sita, ultima saepe 

 conspicua Melolonthidae. 



Stigmata abdominis in membrano inter segmenta ventralia et dorsalia sita, ultima obtecta Pleurosticti. 



Besides this difficulty in determining the limits and characters of the entire family, 

 some difference in observation appears to result from the nature of the characters 

 used in its division. Thus, for example, the ventral segments of the Sericidae are 

 described as free by Erichson and Lacordaire, and as connate by Burmeister; the 

 sutures are in reality distinct, though probably immovable. Nevertheless, although 

 so deceptive, this character cannot in the present condition of the study be abandoned, 

 though perhaps something may be done to render it more reliable. 



Modifying the tables of Erichson and Lacordaire to suit the introduction of the new 

 views enunciated above, and omitting the groups not found in our territory, the 

 following table may be formed : 



I. Mandibulse sub clypeo tectae. 



A. Coxae anticas transversse baud prominulae. 



Parapleurae lata?. 



Segmenta abdominis haud connata . . . . . 1. Macrophyllae. 



Segmenta abdominis suturis obliteratis . . . . . 2. Melolonthae. 

 Parapleurae angustae . . . 3. Rhizotrogi. 



B. Coxae anticae conicae prominulae. 



Parapleurae angustae vel mediocres ; tarsi onycbio distincto ; tibiae posteriores bicalcaratae. 

 Abdomen segmentis ventralibus haud connatis : 



segmentum sextum baud conspicuum . . . . . 4. Diplotaxes. 



segmentum sextum conspicuum. 

 Labrum connatum . . . . . . . . 5. Sericae. 



Labrum distinctum : 



ungues divergentes, fixi . . . . . . . 6. Macrodactyli. 



ungues mobiles, cbeliformes . . . . . . 7. Dichelonychae. 



Abdomen segmentis ventralibus arete connatis . . . 8. Lasiopodes. 

 Parapleural magna?. 



Tarsi onycbio nullo ; tibiae uniealcaratae vel ecalcaratae . . 9. H o p 1 i ae . 



II. Mandibulae ante clypeum conspicuae. 

 Parapleurae maximae (abdomen segmentis liberis) . . . . 10. Grl apby ri . 



