PROBABLE FOOD-PLANTS OF TERTIARY CATERPILLARS. 73 



A species of Delias, however, to which genus Coliates has been specially compared, 

 is stated to feed, not upon a leguminous plant, but upon Dioscorea, one of the Yam 

 family ; and the presence in Aix of a species of a closely allied group, Smilax rotun- 

 diloba Sap., is announced by Count de Saporta. It is not improbable, therefore, 

 that Smilax rotundiloba was the food-plant of the larva of Coliates Proserpina. 1 

 The fifth Aix species is Thaites Ruminiana. It is most nearly allied to Thais 

 of the present day, though it bears certain relations, as we have seen, to neighbor- 

 ing genera. Thais feeds principally at least upon Aristolochia 2 and so, too, do 

 Ornithoptera, Archon and some genera of swallow-tails; indeed, this seems to be 

 a favorite food-plant with insects of this character. Parnassius, however, feeds on 

 Sedum, Telephium, Sempervivum and Coiydalis, especially on the first-named, one 

 of the Crassulacea? ; but nothing very closely allied to this is specified by Sa- 

 porta from Aix; neither, also is Ai'istolochia, but it has been found not only in 

 Radoboj 3 in the Mayencian, but also, according to Heer, at Hohe Rhonen in Swit- 

 zerland, which belongs to the Aquitanian, and has at least one plant (Laurus pri- 

 migenia Ung.) in common with Aix. It seems, therefore, highly probable that 

 either Aristolocliia nervosa Heer, A. Aesculapi Heer, or a distinct species of the 

 genus will yet be discovered at Aix, 4 and may then be considered, as with little 

 question, the food-plant of Thaites Ruminiana. If it be deemed hazardous to ven- 

 ture such an opinion, attention is called to the two following passages ; the first is 

 from the introduction to Heer's paper on the fossil insects of Aix: 5 "Dass indessen 

 auch "NVeiden oder Pappeln [Populus] sich vorhauden, durften der Bythoscopus 

 muscarius und die Aphrophora spumifera [Honioptcra] anzeigen, cleren analoge 

 Irhrnde Arten besonders auf deu Blattern und Zweigen dieser Baume sich umher- 

 treiben." The second is a note in the errata to the translation of Heer's work on 

 the Climate and Vegetation of the Tertiaries 6 by Gaudin: "Le Poacites ciliatus 



1 Since this was written, Count Saporta writes me : ''Le genre ne saurait etre mise en question, depuis quo nous avons enti-e les 

 Smilax est un des genres tertiaires les plus frequents. J'ai aussi mains une superbe empreinte de Radoboj (Aristoloehia venustn 

 signale dans le depot voisin de St. Zacliarie (etage Tongrien infe- Sap.)- qui denote nne forme voisine des Aristoloehes & feuilk's 

 rieiire [and therefore but slightly more repent]) unc feuille qui m'a persistantes et demi-coriaces, comme 1' A . retimlata Nutt. de Vir- 

 paru devoir se ranger parmi les Dioscoiees." ginie." Saporta, loc. cit., 34 L _'-o. 



2 An old writer in Fnessly's Magazin, writing from Italy, says J In a recent letter from Count Saporta he remarks : " Relative- 

 thai Thais feeds in that country upon Querciis. Five species of ment an Thaites Ruminiana, je n'ai pas encore decouvert a Aix de 

 Qnercus are known from Aix, but the statement in Fuessly's Mag- vestiges dti genre Aristolochia, mais ce genre devait y exister." 

 azin lias never, to my knowledge, been runiinncil. B Vierteljahrsschrift naturf. Gesellsch. Znrirh, i, 12, 1856. 



s *' Nous n'avons pas encore rencontre d'Aristohicliia dans les " Uecherches snr le Climat et la Vegetation dn pays tcrtiaire, 



gypsesd'Aix; mais Vexistence dn genre dans le tertiaire moyen 4to, Issl. 



