236 The Irish Naturalist. [Sept., 



LIpura Wrightll (Carpenter). 



L. stilicidii, Wright and Haliday (13). 



I have referred in my introductory remarks to the discovery of a post- 

 antennal organ in this species— the dominant and characteristic insect of 

 Mitchelstown Cave. The organ is harder to make out than in other 

 species of Lipura, but it can be seen in most specimens, after treatment 

 with caustic potash has rendered the head transparent. I have figured 

 the organ in its position on the head (fig. 16), and given a more highly 

 magnified sketch (fig. 17) of an example with fifteen prominences. Some 

 examples have as many as eighteen. Between the organ and the 

 antenna are three ocelliform punctures (fig. 16). 



In Lipiira iner?nis, Tullberg (= L. fimetaria, Lubbock) there are fourteen 

 prominences in the post-antennal organ and two ocelliform punctures. 

 In Z. stilicidii, Schibdte, from the Adelsberg cavern, Carniola, there are 

 also fourteen prominences, but there are three ocelliform punctures as 

 in L. Wrightii. Since my former paper on the Mitchelstown Cave fauna, 

 the Dublin Museum has received specimens of L. stilicidii from Prof. 

 Hamann, of Steglitz. Examination of these leaves no doubt that the 

 structures described and figured by Schiiadte are the prominences of a 

 post-antennal organ, as Tullberg and Lubbock suggested, and not ocelli. 

 Both our Mitchelstown species and L. stilicidii dx^ therefore truly referable 

 to Lipura and not to Aniirophoriis,v^\:i\.z\i, in its modern sense, is restricted 

 to A. laricis, Nicolet, a species with ocelli, but no post-antennal organ. 



L. Wrightii can no longer be differentiated from L. stilicidii by the 

 absence of a post-antennal organ, and it is seen that this structure 

 difi"ers but very slightly in the two forms. Both species have a strongly 

 granular skin covered with bristles. In our specimens of L. stilicidii I 

 find two stout spines on the last abdominal segment. These spines are 

 absent in L. Wrightii. Those present in the Adelsberg species are much 

 smaller than the prominent anal spines characteristic of L. ambulans and 

 other LipurcBy and according to Schiodte's figures copied by Haliday (13) 

 they disappear in perfectly adult specimens. 



Both in L. stilicidii and L. Wrightii the apex of the third antennal 

 segment bears a number of stout curved spines (fig. 18). I have found 

 similar but smaller structures in a corresponding position in Z. ambulans. 

 I can find no mention of these in the literature, and have no idea of their 

 function. Moniez, however (8), states that the apex of the second 

 antennal segment of a French cave-species, Z. cirrigera, bears a tuft of 

 cirrhi which he believes to be some special adaptation to cave life. 

 Beyond the obvious fact that it is some kind of sense-organ, the function 

 of the post-antennal structures is also unknown. 



It is certain that I was mistaken in describing the back margin of the 

 head of Z. Wrighdi as sinuate, as well as in supposing the pronotum to be 

 indented on either side. In the latter error I seem to have followed 

 Haliday ; ii is some consolation to have made a mistake in such excellent 

 company. I was deceived by the lateral projections of the thorax 

 in the first segment, as SchiiJdte seems to have been in all the segments. 

 I have figured (fig. 16) the head and two first thoracic segments as they 

 really are, and in Z. stilicidii they are closely similar. 



