374 Mtscellaneoust 



and that the differentiation of the rodlet- and ganglion-cells takes 

 place very early. 



With reference to the function of this organ in general I am firmly 

 convinced that it does not belong to the category of the so-called 

 olfactory organs of the antenna. I think that my investigations 

 prove that the nerve-eudings are situated in such a way that each 

 movement of the distal portion of the antenna, whether in conse- 

 quence of pressure or tension (Zerrung), must cause a stimulus 

 to be imparted to them. As has been determined by numerous 

 observations and experiments, many insects exhibit with their 

 antenna; a reaction to sound. 



It is true that in many instances these observations are not free 

 from error ; but in spite of this it appears to be very probable that, 

 at any rate in the case of many insects, an auditory organ is con- 

 nected with the antenna. In my opinion the organ which I have 

 investigated may be the auditory organ in question. It was, more- 

 over, years ago regarded a.s such in the case of the Xematoccra. 



The presence of an organ of this nature in the Orthoptera might 

 perhaps teU against this view, since these insects besides these 

 structures also possess others, the tympanic organs, which are 

 usually regarded as an auditory apparatus. Nevertheless I will 

 here merely recall the experiments of Graber*, who found that 

 Orthoptera, even after the excision of the tympanic organs, were 

 still sensitive to sound, and moreover exhibited the reaction with 

 their antennae, in certain cases also with the legs. 



It appears to me that this organ, if susceptible to veri*- small 

 sound-movements, is also stimulated by coarser shocks, e.r^. by 

 contact of the antenna with a solid object ; in short, that in this 

 case there is no sharp distinction between auditory and tactile 

 sensation. 



Since it was impossible for me to foresee that the investigation 

 would extend so far, I collected but little fresh material during the 

 past summer, and was later on prevented from acquiring more 

 in consequence of the advanced season of the year. I intend, 

 however, to ascertain precisely the range of this organ, and to 

 determine its function if possible by experiment. The results of 

 these investigations I purpose to treat in greater detail in a 

 subsequent paper. — Zooloijisclicr Aiizeiger, xvii. Jahrg., No. 439, 

 February 5, lb94, pp. 35-38. 



Researches on the Structure^ Organization, and Classification of tJtc 

 Fossil lieptilia. — Part IX. Section 1. On the Therosuchia. Bv 

 H. G. Seelet, F.R.S. 



This paper discusses the classification of reputed Permian and 

 Triassic lieptilia which have been referred to the Auomodontia as 

 Theriodouts. 



LijcosaurKS, as the genus placed first on Sir E. Owen's list, is 

 accepted as the type of the Theriodontia. The species Lycosaurus 



Deuk; 

 papers 



• Graber, " Ueber die Tympaualsiimesorgiuii.^ dor rthopteren," 

 akschr. der k. Akud. zu U'ieu, uut.-wijs. Thoil, 1S7(5 ; jiud other 



