of the Fishery Board for Scotland. 197 



the inner stations, Ctelenterata were more numerous. This difference 

 does not seem be merely accidental ; it is too general and persistent 

 for that being the case, and is possibly due rather to a difference in the 

 habits of the two kinds of organisms, but the reason, whatever it is, does 

 not appear to be very obvious. An examination of the total numbers of 

 the monthly records of Ctelenterata for each station, as well as for all the 

 six stations, shows one or two other points of difference between the 

 distribution of these organisms and that of Sagitta. In the case of these 

 Coelenterates the lowest numbers of records for any of the six stations are 

 those for March and April, whereas, in the case of Sagitta, the lowest 

 numbers are, with one exception, those for June and July. It will be 

 further observed that, if the numbers of the monthly records are separated 

 to correspond with the inner and the outer stations, ten of the monthly 

 numbers for the inner stations are greater, and some of them considerably 

 greater, than the corresponding numbers for the outer stations, while one 

 of the other two numbers is equal to, and the second only slightly less 

 than, the numbers for the same months for the outer stations, which 

 emphasises still further the difference in the distribution of these 

 Coelenterates between the inner and outer stations. This is more clearly 

 shown by the Formula (2). 



Formula (2) shows the total number of records of Ctenophora and 

 Hydromedusae for each of the twelve months, for (a) the inner stations, 

 I., III., and IV. ; (b) the outer stations, V., VIII., and IX. ; and (c) for 

 all the six stations : — 



Names of the Months, g ,n 



Total number of fW £ e *T r |i at f ionS ' " 

 Records for eaclJ (*> the 0uter btafclons ' ' 



Month, for (^ a]1 the six stationS) . 2 6 28 5 5 19 32 34 36 18 35 28 30 



That Ccelonterates were more numerous at the inner than at the outer 

 stations is still further shown by separating the yearly total numbers so 

 as to correspond with the two groups of stations as in Formula (3). 



Formula (3) shows the total number of records of Ctenophora and 

 Hydromedusae for each of the seven years, for (a) the inner stations, I., 

 III., and IV.; (b) the outer stations, V., VIII., and IX.; and (c) for all 



the six stations : — 



Numbers of the Years, .... 1889. 1890.1891.1892. 1893. 1894.1895. 

 Total number of (M the Inner Stations, 26 29 21 34 39 15 17 



Year, for (^ &u the gix gtationS) 44 42 36 66 60 2 3 25 



This formula shows that the number of yearly records for the outer 

 stations is considerably lower for every year except 1892, when the 

 respective numbers more nearly approximate. The highest number for 

 the inner stations is that for 1893, and for the outer stations the highest 

 number is that for 1892, while the lowest numbers for both are in 1891 

 and 1895. 



(5.) Larval and Young Crustacea. 



The next group of organisms described in the tow-net records which 

 are of numerical importance are the young of various species of Crustacea 

 belonging to the Decapoda, Schizopoda, and Cirripedia. Young and 

 larval Crustacea are generally more or less frequent during the summer 

 months, and sometimes they occur in great abundance, and because of 



a 



1-8 



En 





"u 



< 











 < 



Oh 



m 



-t-3 



o 

 O 



Nov. 

 Dec. 



18 



18 



3 



4 



10 



16 



19 



24 



8 



21 



20 20 



8 



10 



2 



1 



9 



16 



15 



12 



10 



14 



8 10 



