210 Prof. E. Warren. On the Development of tlw 



Coincidences of Vanadium Lines with Lines of other Metals. 



A 



(Kensing- 

 ton). 



• • 



Origin 



or 



coincident 

 line. 



Int. 

 in 

 Y. 



Int. of 

 coincident 

 line. 



. : 



A 



(Kensing- 

 ton). 



Origin 

 0± 



coincident 

 i • „ 

 .ane. 







Int. 

 in 

 Y. 



Int. of 

 coincident 

 line. 



3894 lb 



Or 







4-5 



4 



442/ *49 



Fe 







4 



7 



3913 ' 71 



Fe 



1 



2-3 



67 '09 



LO 



2-3 



4 



/ / 8o 



if e 



2 



4-5 



97 "00 



Lr 



4 



5-6 



4052 "60 



Mn 



1 



4 1 



4514 "36 



Jbe 



4 



< 1 



68 '16 



he [ Mn 



2-3 



o 1 o 



17 '75 



±< e 



3 



1 



70 -94 



Fe 



2-3 



2-3 



25 -33 



Fe 



3-4 



4 



83 -07 



Mn 



3-4 



7 



34 -08 



Co 



3 



4 



90 -05 



Mn 



1 



4 



49-79 



Co 



6 



5 



90-74 



Mn 



8 



1-2 



4603 -15 



Fe 



1 



5 



, 4224-36 



Fe 



3-4 



3 



26 -66 



Mn 



4-5 



- 5 



34 -18 



Co 



5-6 



1-2 



54 -80 



Fe 



1 



4 



4408-35 



Mn 



5 



4 



4709 -93 



Mn 



2-3 



7 



15-25 



Fe 



3 



10 



4871 -50 



Fe 



2 



6 



" A Preliminary Account of tlie Development of the Free- 

 swimming Nauplius of Leptodoro, hycdina (Lillj.)." By 

 Ernest Warren, D.Sc, Assistant Professor of Zoology, 

 University College, London. Communicated by Professor 

 Weldox, F.R.S. Received February 4, — Read February 28, 

 1901. 



Leptodora appears to be a primitive claphnid in retaining a long, 

 markedly segmented abdomen, and for this reason it seemed likely that 

 an investigation on the development of the winter-generation might 

 throw some light on the vexed questions in Crustacean development. It 

 was more particularly desired to ascertain whether any vestige of a 

 ccelom occurred, and that if so, whether any remnant of it persists in 

 the adult. With this object in view, it was necessary to inquire into the 

 origin of the genital cells and of the antennary and maxillary glands. 



In April, 1898, Professor Hickson obtained a few nauplii from Lake 

 Bassenthwaite, Cumberland, and later in the year a large number of 

 adults. This material was most generously placed at my disposal by 

 Professor Weldon, and I wish to express to him my sincere thanks. 



The material was insufficient for my purpose ; and in the following- 

 spring I visited Lake Bassenthwaite to try to obtain fresh material, 

 but I met with very little success. Last spring, however, sufficient 

 material was obtained to continue the investigation.* The preserving 

 reagent employed was Flemming's solution (strong formula). 



* I am indebted to the Royal Society for a Government Grant in connection 

 with obtaining this material. 



