167 



over or among the upper hypodermal cells which at times, owing to 

 the indistinctness of the cell outline of the latter, can with difficulty 

 be distinguished from them. This is the case especially in sections 

 where the glandular structures are not in abundance. 



In sections through the posterior segments of these specimens the 

 distinction between nerve and hypodermal tissue is again obscured and 

 the condition there is not unlike that in specimens of ^w^'o/y^e^s through- 

 out the ventral region. In following successive sections back toward 

 the posterior end of the animal the hypodermis and ventral cord are 

 seen to gradually approach one another, the gland structures become 

 less numerous and no longer afford a boundary line between the two 

 tissues until in more posterior sections they disappear altogether and 

 ganglion and hypodermal cells merge into a single, rather thick tissue. 

 Back still farther the nerve cord sinks into this thickened tissue and 

 the latter assumes the characters common to recently formed segments. 



In the head of these specimens I have not been able to make any 

 distinction whatever between the hypodermis and ganglion cells, and 

 the outlines of the former cells appear abruptly wherever external ap- 

 pearances mark the beginning of structures that do not belong exclu- 

 sively to the head proper. 



The distinction between ganglion and hypodermal tissue in Pro- 

 ceraea, Mn\\\ie Autolytus, seems possible therefore in such regions where 

 a great development of gland structure is present as an aid to the dif- 

 ferentiation. 



Ursinus College, Collegeville, Pa., U. S. A. Marche, 1899. 



II. Mlttheilungen aus Museen, Instituten etc. 



1. Zoological Society of London. 



2 Ist March, 1899. — Mr. E, T. Newton, F.R.S., exhibited and made 

 remarks upon some fossil remains of a Mouse from Ightham, Kent. He 

 pointed out that the name under which he had described the specimens in 

 1894, viz. Mus Abbotti^ had been previously employed by Waterhouse for a 

 Mouse from Trebizond, and that he proposed to substitute Mus Leioisi for 

 that name. — A communication was read from Dr. G. Stewardson Brady, 

 C.M.Z.S., containing an account of the Copepoda collected, chiefly by means 

 of the surface-net, by Mr. G. M. Thomson, of Dunedin, and by Mr, H. Suter, 

 on behalf of the Zoological Museum of Copenhagen. It was shown that 

 several species were identical with well-known European forms, and others 

 were closely allied, but many were entirely distinct and presented very inter- 

 esting peculiarities. — Mr. W. P. Pycraft gave an account of the osteology 

 of the Tubinares. He pointed out the Stork-like character of the group, 

 which hat not been before emphasized, so far as regards osteological features. 

 — Mr. F. E. Blaauw, C.M.Z.S., gave an account of the breeding of the 

 Weka Rail [Ocydromus aus(ralis) and Snow-Goose [Chen hyperboreus] in his 



