284 THE entomologist's record. 



The egg-case of Pahjphaga aegyptiaca (sub-family Conjdiinae) has 

 been figured byBrunner von Wattenwyl in his Frodruinus Knropaiscketi 

 Ort/iojitcrfH (pi. i., fig. 12 C.) ; it is chiefly remarkable for being 

 furnished with a peculiar flange or spur at the posterior end of the 

 sutural crest, which is deeply notched; it is not so rotund as the 

 typical Blattine ootheca, but is rather intermediate in shape between 

 such an one and that of Me(jalnblatta. There is no information as to 

 the way in which the ootheca is carried, i.e., with the suture upper- 

 most or directed to one side. 



The corresponding Neotropical genus Honweor/aniia has a very 

 peculiar ootheca, if one may take that of H. azteca as an example. In 

 shape it is not unlike that of Parotnijies hilunata, but along the lower 

 border on each side runs a thin flange, leaving between them_a deep 

 groove. The capsule is carried in the same way as in the Ni/ctiborinae. 



On account of the egg-laying habits of the Blattidae and Mantidae, 

 Handlirsch, the learned Viennese entomologist, has brigaded together 

 these two families of Orthoptera, christening them the lUattacfoDiiia 

 Oot/ieraria and regarding them as the most primitive of all the 

 families. From an anatomical point of view this opinion may 

 be correct, but it is a mistake to suppose that all Blattidae form 

 an ootheca. The case is far otherwise, and I can state with 

 confidence that about one-third of the genera form no ootheca at 

 all, or only a most imperfect one, the young larva? emerging alive 

 from the brood-sac of the mother. The viviparous habit amongst 

 cockroaches was first discovered by Riley in Panchlora riridis, and 

 numerous other examples have come to light since then. In most of 

 these viviparous species the embryos are carried in the brood-sac of 

 the mother enveloped in a thin membrane, which ruptures to let the 

 embryos escape. But yet another method has been observed by 

 Holmgren of species belonging to three subfamilies, riz., O.rijkaloa 

 saiissnrei {( Knjhaloinae) , Kiintega^ta niicans (^Kpilaiiiprinae), and Blahera 

 sp. [lUaherinae). In the last species a chitinous, sculptured capsule 

 is formed and is retained in the brood-sac until the young are ready to 

 emerge, when apparently it is deposited. In Euntenaata on the other 

 hand the capsule splits open inside the brood-sac allowing the young 

 to escape before the ootheca itself is actually got rid of. This type of 

 viviparity is evidently secondary to the formation of a chitinous ootheca, 

 or in other words, is derived from it, for it is not reasonable to suppose 

 that an elaborate structure like the ootheca of Mef/alobUitta nijipes 

 should have been developed if it was never to be exposed to view. It 

 is far more likely that the I-'Jiistetjasta and JUabera type of egg-laying is 

 a secondary device to secure still greater immunity from the attacks of 

 parasites, and it is no wild supposition that in course of time the 

 chitinous ootheca, being in these species a work of supererogation, will 

 disappear. The viviparity of I'anchloia and I'anesthia is another 

 matter ; it may be primitive, it may be derived from the Kustegaata 

 type or from yet another type of ootheca, eiz., that shown by Blattella 

 fiennanica and other B.seitduiiiopinae. The ootheca of B. (jermanica is a 

 thin leather sac, and carried with the suture, which is not marked with 

 any crest, directed to one side, the number of contained eggs is rather 

 large and therefore the length of the sac is considerable. The sutural 

 line is marked by a series of puckers and the number of eggs is about 

 fifty. This structure is carried in a brood-sac and protruding from 



