256 NOTES ON THE FAUNA OF FALMOUTH. 



were observed. The same parasite has been observed in the 

 structureless layer of Tiara octona, but has always been found 

 wanting in the Siphonophores. I have spent a considerable 

 amount of time during two summers in attempting to trace the 

 further developmental changes of this singular parasite, but so 

 far I have been unsuccessful. The following is a brief 

 description of this larval form. The average length of a fully 

 expanded specimen is 1 m.m. The body is annulated, and 

 covered externally by an immense number of bodies resembling 

 tactile setoe. Owing to the opacity'of the integument one cannot 

 trace very closely the course of the gut ; the following parts are, 

 however, easily distinguishable in the living animal. An oval 

 shaped mouth placed at the anterior extremity immediately 

 passes into a muscular pharynx ; beyond this one is unable to 

 see anything definite. The anus, which is placed at the other 

 extremity, is median and terminal. The most striking feature 

 about the animal is the presence of a comparatively large and 

 powerful sucker, which is placed mid-way between the two 

 extremities on the ventral aspect. In nearly all the living 

 specimens there were numerous highly refractive bodies 

 occupying the posterior third of the body. 



On the 21st, two diatoms, Choetoceros and Ehizosolenia, 

 began to appear in a gathering made about three miles S.E. of 

 the harbour ; and during the two following months were never 

 absent from surface-net gatherings. On the same day, 21st, two 

 specimens of Corycoeus anglicus each with ova attached were 

 secured. A solitary specimen of Tiara octona, measuring 

 upwards of 18 m.m. in height, was dipped from the sea close to 

 the lighthouse on the 24th. Strangely enough, this was the 

 only specimen seen during this year. 



June. A still further rise in the surface temperature of the 

 sea was again observed during the whole month. On the 1st 

 the surface temperature of the sea at 10 a.m. was 56°F. ; on the 

 4th, 58T. ; 5th, 58-9°r. ; 8th, 59°F. ; 10th, 59-9°F. On the 

 12th, a series of surface temperatures were taken in the neigh- 

 bourhood of the following places : — 1 mile due south of Coverack 

 at 12.30, 56°F.; 1^ miles south-east of the Lizard, 55-3°F.; and 

 close to the Manacle buoy at 3 p.m., 56 °F. Returning now to 

 Falmouth harbour. The surface temperature on the 1 7th was 



