FROM THE society's GARDENS. 653 



Tlirough the generosity of Mr. Waterston I have been nble to 

 prepare, dissect, and mount a considerable number of Philopteri 

 of this group from a variety of hosts, the following distinct 

 species emerging as a result : — Philopterus cygni D. (on Swans), 

 P. hrunneiceps G. (on Geese), P. icterocles N. (on different species 

 of Ducks), P . ferrugineus G. (on Ducks), P. ohtusus G. (on Soma- 

 teria mollissima (Linn.)), and a species taken on the Pochard, 

 which I cannot name satisfactorily and must therefore regard 

 as new. 



The whole group, for which the new genus Anatcectis is 

 proposed, is a remarkably compact one, and the species com- 

 prised in it are all closely related and sometimes with difficulty 

 differentiated one from another ; so that Giebel's specific diagnoses 

 are of little assistance, even for the purposes of identification. 

 Further, as straggling occui-s so frequentfy from Duck to Duck, 

 it is unsafe to rely for help upon the host's name. 



The above identifications, thei-efore, must be accepted with 

 reserve. Rather than give new names, it has appeared better to 

 perpetuate the old where that was possible, at the same time 

 figuring the parts important for the differentiation of the species. 

 In the future, should the types of Giebel and of Nitzsch become 

 accessible, these decisions can be revised if necessary. 



Anat<i;cus, gen. nov. 



Head distinguished by the chara,cteristic alation of the clypeus, 

 by the presence of two small peg-like spines dorsally (one on each 

 side of the postei-ior apex of the signatural plate *), by the 

 unusually short antennpe, and the modified lyriform organ. 

 Abdomen characterised by the form of the lateral tergites, which 

 in segment 1 meet each other in the middle line. In subsequent 

 sections, except the last, the tergites leave an uncovered median 

 field. In the male copulatory apparatus, the fusion of the 

 parameres distally with the pseudopenis, the form of the latter, 

 the endomeral plate, and sac are also good generic characters. 

 Finally, the form of the vesicula semincdis and the extremely 

 short ductus must be included. 



Small ectoparasites, infesting Swans, Geese, and Ducks. 



A genus indicating in the male genitalia certain Lipeuroid 

 affinities, and in the mouth-parts obvious affinities with the 

 genus Ibidoscus, nov. 



Genotype : Anatoecus icterodes Nitzsch. 



The six species distinguished up to the present (no doubt others 

 remain to be elucidated) fall into two groups, according as tlie 

 effractor — a remarkable structui'e shaped like a tin-opener — is 

 present or absent on the endomeral plate of the male. A. Those 

 with the "tin-opener" are A. fennighietis and A. ohtusus. 

 B. Those without it are A. cygni, A. icterodes, A. hrunneiceps, 

 and A. difficilis, sp. n. 



* The whole of the dorsal clijetotaxy of the head is a g-ejieric character. 



