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Part III. — Seventh Annual Report 



Numerous Nauplii likewise occurred, and examples of the Megalops- 

 stage of the higher crustaceans, as well as a young stage of Hippolyte 

 securifrons ^ inch long. 



In the mid-water net the only annelid observed was Tomopteris onisci- 

 formis, which once appeared in considerable numbers, and fully an inch in 

 length. Numerous ova occurred in the perivisceral diverticula of the feet. 



[At this time the ground, trawl gave Eulalia viridis and Autolytus 

 prolifer in a budding condition.] 



Sagittse were occasionally obtained in the mid-water net, but they were 

 comparatively few and small, only the larger forms reaching to 15 mm. or 

 f of an inch. This, therefore, was in marked contrast with the condition 

 during the winter months, when the Bay teemed with large and active 

 Sagittse. 



The larval annelids included Nerine, Leucodore, and the young of Spio 

 in great numbers. The abundance of the larval annelids in the pelagic 

 condition makes a notable addition to the food of the post-larval fishes. 

 Many of these pelagic annelids are readily visible to the naked eye. 



The vast numbers of Appendicularians characteristic of the preceding 

 month gradually disappeared, and only a few small examples (Plate IV. 

 fig. 9) now and then were secured in the mid-water and bottom-nets. The 

 sudden appearance and almost as sudden disappearance of these forms is 

 an interesting problem, and from the regularity of their advent in spring 

 other causes than the effects of currents are probably involved. 



Cyphonautes was rather plentiful this month, especially towards its 

 close, and always in the bottom tow-net. 



Pelagic young mussels appeared in the bottom tow-nets about the latter 

 third of the month, and perhaps even sooner, but in comparatively small 

 numbers, and they were first procured in the bottom-net off the Eden 

 whence they probably radiated throughout the Bay. Their size varied 

 from *0055 to "014 inch. Nearer the end of the month the measurements 

 of three average forms were as follows : — y^-, and of an inch. 

 The young mussels in the Bay kept to the lower regions of the water. 



Spinalis, both in the adult and young condition, abounded in the 

 bottom-nets, the larval forms being very numerous. Other minute uni- 

 valves were abundant. 



The very young flounders (9 to 12 mm.) procured in the mid- water net on 

 the 1st, had the embryonic tail and the projecting abdomen, showing that 

 they were in the early post-larval stage. The eyes were lateral, the left 

 just a little in advance of the right. The length of the least was about 

 7 '5 mm. A very early post-larval form only 6*2 mm., with two others (9 

 and 10 mm.) was got on the 13th. In the latter a median line of black 

 pigment occurs on the ventral surface, from the branchiostegal region 

 backward, and it remains in spirit. The frequency of this black ventral 

 pigment in early post-larval forms is noteworthy. 



The young gadoids still remained conspicuous features of the pelagic 

 fauna during June, and they ranged from 7 mm. with an entire marginal 

 fin to 24 mm. They fed on Nauplii and Copepods. Some of the smaller 

 of these were of a shorter and stouter formation, with a shorter snout 

 and heavier head, and the permanent rays of the fins seemed to be far 

 advanced^for their size. Their jaws appeared to be less lanky than those 

 of the cod, but whether they are mere varieties, or represent the haddock, is 

 unknown. Young cod (ly^ inch), with more or less tessellated pigment on 

 the sides, occurred in the mid- water net on the 15th; while, as mentioned 

 subsequently, somewhat older forms were captured in the ground-trawl. 



In the surface-net of 11th June a most minute ovum, "027 of an inch, 

 with a single oil-globule '005 of an inch, occurred. It is less than that of 



