65.2' MR. 15. F. CUMMINGS ON LICE 



biisal [jlate, is a short stout penis-like tube foi-med of two distinct 

 longitudinal halves. Each half is densely chitinised and dark 

 brown in colour, and at the base spreads oat towards the base 

 of the paramere. This tube is perhaps homolo.sfous with the 

 transverse piece of P. ceUehrachys and other Owl Philopteri (see 

 text-figs. 1 & 2). The endomeral plate corresponding with the 

 same p'ece in the Owl Philopteri overlies the rest of the inesosome 

 and bridges across from the base of one paramere to the other. 

 The dustus ejaculatorius runs in under the bridge. The endomeral 

 plate may either consist of two pieces superimposed upon one 

 another — viz., the deeply bifid band marked in the text-figure 

 and the plate above this stretching across from pai-amere to 

 paramere ; or these parts may only be sculpturing or local thick- 

 enino's in the same plate of ehitin. 



AUmentarj/ Canal (text-fig. 6). — This belongs to the common 

 Ischnoceran type figured by Snodgrass (1, pi. xi. fig. 11). But the 

 crop is longer and narrow, and in the ventriculus immediately 

 behind the two anterior cieca there is a deep constriction, below 

 which the ivntriculus is broad and spacious. 



The Philoptkri of Ducks, Geese, and Swans. 



This interesting group of Mallophaga was first seriously tackled 

 by Giebel in the ' Insecta Epizoa,' 1874 (5, pp. 113-1 16), in which 

 eight distinct species are described, including the typical Philo- 

 2Jterus icterodes. Denny (8, pp. 95 & 99) described two other 

 species — F. cygid from Cyynus betvicki Yari-. and P. chryso- 

 phthahni from Glaucion clangula (Linn.) (Clangula chryso- 

 jihthahni). By i-eference to Denny's collection, now in the 

 British Museum, his " B. chrysophthalini " proves to be an 

 Accipitrine parasite, probably P. pictus^ a sti'aggler perhaps 

 npon the Golden-eye Duck ; or Denny may have niisread 

 or confused his label, mistaking- "Golden-eye" for "Golden 

 Eagle." Giebei remarks, of the form figured and described by 

 Denny under the name " X>. icierodes" th-At "seine Abbildung 

 giebt so erhebiicoe Diffei'enzen an, dass man gerechte Zweifel an 

 der Identitat erheben konnte." I have examined Denny's spe- 

 cimens, and find, as Giebel suspected, that Denny did not have 

 P. icterodes before him. His specimens belong to the form 

 which, until the types of Giebel and Nitzsch can be re-examined, 

 I propose to identify with Giebel's P. ferrugineus. Piaget (3, 

 pp. 113-116) was imperfectly acquainted with these Duck 

 parasites. He describes and figures true P. icterodes, I think 

 correctly, altliough the sketch of the terminal segments of the 

 abdomen of the male (pi. x. fig. 1 a) appears to show the remark- 

 able structure on the endomeral plate described below and called 

 the efiractor, which is present in P. ferrugineus but absent in 

 P. icterodes. Piaget did not know any of Giebel's species, and 

 subsequent authors have labelled all Philopteri from Geese and 

 Ducks P. icterodes. 



