176 Part [II.—Sixteenth Annual Report 
and they either remained in the estuary all the summer or returned in the 
autumn, for they were observed again in November. 
Whether this irruption of the Hyperiide was merely accidental and 
temporary, or due to a periodic migration at more or less distant inter- 
vals of time, the records are not sufficiently extensive toshow. Whatever 
be the reason, there seems to be no doubt that some time during 1891 and 
1892 there was a greater number than usual of these Crustaceans off our 
Kast Coast, part of which found their way inshore, with the result that 
the number of records of Parathemisto was increased beyond those of the 
previous or following years. 
In the following analysis of the Table, some of the results referred to 
are more clearly brought out—the three formule subjoined show the 
total numbers of the records (1) for the stations, (2) the months, and (3) 
the years, thus :— 
Formula (1) shows the total number of the records of Parathemsto 
for each of the stations for all the months and years :— 
Numbers of the Stations, 4 IL. TEE LV. Vv. WAL E IX. 
Total number of Records for dabh Station, : By 88) Bit 36 36 29 
Formula (2) shows the total number of the records of Parathemsto 
for each of the months for all the years, (a) for Stations L, IIL, and IV. ; 
(6) for Stations V., VITI., and IX. ; and (c) for all the six stations: — 
Names of the Months, Ac a = bp =f 8 
ic SS Sis a SS 
(a) the Inner Stations, - 16 18 10M 73 Oy 5. Oe 
Tota! number of J (0) the Outer Stations, - 1020 814 6 3 1 2 Ooms 
each Month, for { (.) a1] the Six Stations, - 26 38 18:29 13 6 1 7.016 19 36 
Formula (3) shows the total number of the records of Parathemisto 
for each year, for (a) the inner stations, I., III., and IV.; (0) the outer 
stations, V., VIII, and IX. ; and (c) for all the six stations :— 
Numbers of Years, - Srl ees - 1889. 1290. 1891. 1892. 1893. 1894. $1895: 
(a) the Inner Stations, - 2 4 B40 987 ~ 
Fotal number of 16) the Outer Stations,,. 6 12° ©2053 | 17) ac 
Records for 
each Year, for 
(c) all the Six Stations, 8. 16,. 54 . 60.) 84.) /20uummme 
Huthemisto compressa. This species (referred to above) was recorded 
for the first time in the Firth of Forth in the “ Tenth Annual Report of 
the Fishery Board for Scotland,” from specimens obtained at Station V. 
in February 1892. It was collected again in the same year in November; 
and the next record of it is in November 1893, when it was obtained at 
Station V. 
The other Amphipods mentioned in the list are, with the exception of 
Paratylus and Apherusa, only occasionally referred to among the records 
of tow-net invertebrates, and are therefore, except from a natural history 
point of view, of less importance than those already mentioned. 
Consequently J do not propose to enter very minutely into the 
consideration of their distribution.* 
Callisoma crenata. There are few records of this species, and they 
extend from 1890 to 1895. 
Hippomedon uenticulatus is only recorded once among the tow-net 
lists for the selected stations—viz., for Station IX. in February 1894. 
* A tabulated list of species at the end of this paper shows some further details of the 
distribution of these Amphipods, 
