198 NOTES ON THE FAUNA OF FALMOUTH. 



The average surface temperature of the sea for the month 

 was low and varied hut little, remaining almost stationary from 

 the 1st to the 23rd at 53-6° F., rising on the 24th to 54-9° F., 

 and still further to 56 •6'^ F. on the 26th, at which point it 

 remained unchanged till the close of the month. 



By far the most abundant forms in the tow-net during this 

 month were Sarsia prolif era, which occurred in immense profu- 

 sion in some sheltered j)laces in the harbour. Towards the end 

 of the month, larval annelids began to abound, and with these a 

 few tube-dwelling Terebellids were noticed. The early forms of 

 various species of polychsete larvae were fairly common after the 

 middle of the month. Halospheera viridis was not detected in any 

 of the gatherings after the 24th. Several small Beroe averaging 

 3mm in length were observed on the 25th, and after that date one 

 or two specimens were seen in almost every gathering till 

 September. 



The occurrence of that singular larval form, Ectinosphera 

 diaphana in the tow-net on the 25th is interesting. I have not 

 seen a specimen for a considerable time. The first Actinotrocha 

 larva seen for the year being secured on the same date. 



Jime. On the 1st the surface temperature of the sea was 

 55° F., but on the 3rd it had fallen to 54-6° F. From this day 

 there was a decided change for the better. On the 4th 54"3°P. 

 was recorded, and on the 7th 55'6*^F. ; the temperature after that 

 rose with leaps and bounds, 58"9° F. being recorded on the 15th, 

 and for the first time for the season 60° F. was reached on the 

 1 7th. From the 20th to the 25th there was a steady fall to 56«F., 

 and this was quickly followed by a still further decrease to 53*9 °F. 

 on the 28th: 55'6°F. being recorded on the 30th, the last day of 

 the month. 



About the 15th Obelia lucifera and Auricularia larvae were 

 abundant, and with these Sarsia gemmifera were noticed. 



About this time I detected two specimens of a singular para- 

 sitic Nematode belonging probably to the family Desmoscolecidse 

 wandering in the structureless layer of the umbrella of a Olytia 

 Johnstonii. Unfortunately the host was killed before these para- 

 sites were detected, and as no others were seen, no further 

 observations can be recorded. 



