331 



a clearly defined vessel, the aorta, that pursues its way forward be- 

 tween the halves of the gonad to the head cavity that posteriorly is 

 separated by a diaphragm as well developed as in the chitons. From 

 this space the blood makes its way backward by the pedal sinus and 

 the connected visceral cavity to the branchiae that in their relations 

 and general appearance are of the ordinary type. Each gill has 28 — 

 3 lamellae and is innervated by two nerves from the superior poster- 

 ior ganglion. 



The globular bilobed brain, to which are attached five pairs of 

 accessory ganglia innervating the frontal sense organ, is situated dor- 

 sal to the buccal tube. From it arise three pairs of connectives, the 

 pedal palliai and buccal. In the region of the cloaca the pedal and 

 palliai ganglia unite and are connected by commissures with the sup- 

 erior posterior ganglion located above the rectum. The buccal connec- 

 tives unite on each side of the salivary glands with the buccal ganglia 

 that are also connected by the usual sub-oesophageal commissure and 

 by another passing dorsal to the gut. Very close to the front end of 

 each ganglion a commissure arises that passes round the forward wall 

 of the pharynx and innervates the subradular organ. The relations of 

 this important feature of the nervous system will be described in ano- 

 ther paper. 



From the foregoing it will be seen that the more important cha- 

 racters of the genus Limifossor are as follows: Body short, length in- 

 dex 1 : G. Radula very large, of the distichous type with 28 transverse 

 rows. Dorsal salivary glands present. Stomach and liver well developed 

 and distinct from the relatively long slender intestine 3. 



4. Über die systematische Stellung von Polyarthra fusiformis Spencer^ 



Yon Stan. HI a va, Assistent am Museum Prag. 



(Mit 4 Figuren.) 



eingeg. 15, Oktober 1904. 



In den letzten zwei Jahren habe ich mich während der Sommer- 

 monate etwas eingehender mit der Fauna der Torfwässer Siidböhmens 

 und zwar hauptsächlich mit Rücksicht auf die Rädertiere beschäftigt. 

 Besonders lenkten meine Aufmerksamkeit kleine Wasserbecken auf 

 dem ausgedehnten Torfgrunde zwischen Borkowitz und Mazitz bei 

 Wesseli an der Luznitz, der unter dem Namen »Blata« bekannt ist. 

 Es befindet sich hier eine ganze Reihe solcher Wasserbecken, welche 

 kaum eine Ausdehnung von 4 qm erreichen, dabei jedoch ziemlich tief 



3 This diagnosis applies accurately to another as yet undescribed species be- 

 longing to this genus. 



