56 BRITISH LEPIDOPTEKA. 



(2) A longitudinal line which is apparently continuous on the 8th and 9th sterna 

 — Vanessa io. (The essential difference between this and the preceding depends on 

 the formation of a median furrow corresponding to the course of the azygos oviduct 

 by which the two typical linear depressions seen in Pieris are effectually obscured. 

 The inner aspect of the empty cuticle of V. io shows the remnants of the chitinous 

 linings of the duct of the bursa copulatrix and of the oviduct respectively, at a late 

 stage of growth, however, and, therefore, of greater extent than in the newly-formed 

 pupa. Still they indicate the existence of the structures evidenced outwardly in 

 Pier is.) 



(3) The 9th somite very narrow ventrally and crossed by a line as in Vanessa. 

 The ventral portion of the 8th somite broader, a line extending forwards from its 

 hind margin for about one-third of its breadth — Papilio machaon. 



(4) The 9th sternal region prolonged forwards to a greater or less extent as a 

 triangular plate, invading the 8th sternal region, and, at the same time, not clearly 

 limited from the 10th somite behind, i.e., the intersegmental line between the 9th 

 and 10th somites is not quite continuous from side to side across the ventral line. 

 a. Two fine longitudinal lines or depressions, one in 8th sternum, and a second, 

 shorter one, at the apex of the triangular forward extension of the 9th sternum — 

 Protoparce mauritii. b. A single linear depression in the sternal region of the 8th 

 somite, enclosed by triangular lines passing backwards — Sphinx ligustri. 



Jackson says that the single depression in Sphinx represents the 

 two depressions in Protoparce. He came to this conclusion (1) from 

 the dissection of a pnpa (one day old) of Sphinx ligustri, which showed 

 the existence of exactly the same parts as those seen in Vanessa io, 

 viz., an anterior vesicle with rudiments of a bursa copulatrix and 

 receptaculum seminis, and a posterior double vesicle ; the anterior and 

 posterior vesicles being more closely opposed to each other than in 

 V. io. (2) By finding in the cast pupal cuticles of Sphinx ligustri and 

 Smerinthus ocellatus, two bands united at their bases which are evi- 

 dently the cast chitinoid linings of the ducts of the bursa copulatrix 

 and of the oviducal tube, and which were with the structures figured 

 in V. io. (3) The occurrence of a single or of a double depression in 

 the chrysalids of the same or allied species. Examples of the two 

 forms are noted as occurring in Sphinx ligustri, Smerinthus ocellatus, S. 

 populi, Cossits lignipercla, Zeuzera pyrina, &c. It is further noted that 

 the female pupa of Cucullia verbasci has but one depression, whilst that 

 of C. scrophulariae has two, and Triaena tridens has one, whilst T. psi 

 has two. 



The following Heterocerous female pupa? are noted by Jackson as having 

 two depressions: — Acherontia atropos (5 examples), Sphinx convolvuli 

 (1), S. ligustri (1), Deilephila euphorbiac (2), Choerocampa porcellus (2), 

 C. elpenor (52), C. alecto (1), C. nerii (2), Smerinthus ocellatus (1), 

 S. populi (3), Protoparce mauritii (1), T)aphnis horsfeldii (1), Cossus 

 lignipercla (1), Zeuzera pyrina (1), Cucullia scrophulariae (1), Triaena 

 psi (1), Nyssia zonaria (4). The species that he notes as having but one 

 depression are — Acherontia atropos (2), Sphinx ligustri (many), Choero- 

 campa elpenor (2), Smerinthus ocellatus (many), S. populi (many), 

 S. tiliae (20), Euchclia jacobaeae (11), Arctia caia(23), Cossus lignipercla 

 (2), Zeuzera pyrina (1), Stauropus fagi (1), Leiocampa dictaeoides (2), 

 Notodonta dromedarius (1), Leucania straminea (1), Phalera bucephala 

 (1), 'Triaena tridens (1), Gortyna ochracea (1), Mamestra brassicae 

 (many), ill. persicariae (15), Panolis piniperda (1), Dianthoecia irre- 

 gularis (5), Miselia oxyacanthae (1), Agriopis aprilina (1), Hadena 

 glauca (3), H. trifolii (13), Cucullia verbasci (many), C. umbratica (1), 

 Gonoptera libatrix (3), Selenia tetralunaria (illustraria) (2), Nyssia 

 zonaria (18), Biston hirtaria (13). 



We have, in these organs, probably, characters of the highest phylo- 



