MARINE BIOLOGICAL STATION AT PORT ERIN. 61 



and it buds off new individuals which all live together in the 

 cavities of a hollow gelatinous coenoecium, which they have 

 jointly secreted. Dr. Harmer has shown that the regions 

 of the body and the divisions of the coelom correspond closely 

 with those of Balanoglossus, and that there is a tubular 

 notochord extending forwards from the pharynx to strengthen 

 the proboscis region. 



Amongst the Tunicata many remarkable new abyssal 

 forms were obtained, which have added greatly to our know- 

 ledge of the range of structure in the group. For example, 

 the new genus, Octacnemus, first described by Moseley, has 

 a much reduced and degenerate branchial sac, and has required 

 the formation of a new family. Then, again, several distinct 

 genera, Pharyngodictyon amongst Compound Ascidians, and 

 Culeolus, Fungulus and Bathyoncus amongst Ascidiae Simplices, 

 have the branchial sac simplified by the total absence of the 

 system of fine inter-stigmatic vessels, the result being that 

 the wall of the organ is reduced to a net-work of very large 

 meshes, in most cases strengthened by branched and curved 

 calcareous spicules. These are all of them abyssal forms, 

 and no such structure of the branchial sac has been found 

 in shallow water Ascidians. Very many of the deep-sea 

 Ascidians, including the new genera Culeolus, Fungulus, 

 Ascopera, Hyjpobythius and Corynascidia, are pedunculated, 

 as if they required to be supported upon stalks above the 

 soft ooze in which their bases are entangled and upon which 

 the animals evidently feed. The intestines are found distended 

 with, in some cases, Globigerina and, in others, Radiolarian 

 or Diatomaceous ooze. Amongst pelagic Tunicates a note- 

 worthy form is a new Pyrosoma of gigantic size, of which 

 a magnificient specimen, measuring over four feet in length, 

 was obtained in the North Atlantic, but of which unfortunately, 

 only fragments were preserved. Moseley, in his delightful 

 book, " Notes by a Naturalist,'' tells us that the officers 



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