26 



derm gar nicht ; erwähnt. Das letztere bildet einen sehr Avichtigen 

 Punct in der Structur der Brachiopoden. 



In Folge dessen halte ich mich für berechtigt, den Vorwurf, den 

 Schulgin mir macht, zurückweisen zu dürfen. 



Zoologisches Institut. Freiburg i. B., 18. November 1884. 



III. Mittheilungen aus Museen, Instituten etc. 



1. Linnean Society of New South Wales. 



2 9tli October, 1884. 1. Suggestions as to the Mode of Formation of 

 Barrier-Reefs in Bougainville-Straits, Solomon Group. By H. B. Guppy, 

 M.B., Surgeon R.N. The Author confines his remarks to the Shortland 

 Islands, the main Island of which »Alu«, is composed of volcanic and coral 

 formations , and upon it are two inland ridges representing ancient lines of 

 Barrier-Reefs built upon consolidated calcareous ooze; whilst to the South- 

 east of the Island are two lines of elevated Barrier-Reefs with interior lagoon 

 channels. The Author states that these Barrier-Reefs have evidently been 

 formed during a period af upheaval , and that the intervening channels re- 

 present belts of detritus upon which the reef-building corals could not live ; 

 and he arrives at the conclusion that in the case of reefs which possess such 

 a gradual slope that the lower margin of this band of detritus lies within the 

 zone of reef building corals , a line of barrier reef will be ultimately formed 

 beyond this band with a deep channel inside ; but that in the case of reefs 

 which possess a more rapid sub-marine slope , so that the lower limit of the 

 band of detritus extends far beyond the depths in which the Reef Corals 

 thrive, no such Barrier Reef will be formed. He also thinks it probable that 

 Coral Reefs may commence to build in depths greater than those usually 

 assigned. — 2. Note on a Beroid of Port Jackson. By R. von Lenden- 

 feld, Ph.D. The subject of the paper, N'eis cordiffera I^esson , was descri- 

 bed from a specimen captured in Port Jackson in 1824 by the naturalists of 

 the Coquille , and there is no record of its having ever been seen since until 

 a few weeks ago. Nets represents a genus quite distinct from Beroe. Its 

 sexual cells are matured in the vascular reticulation exclusively, to which 

 place the ova migrate from the meridional canals. The style cells described 

 as sensitive elements by B. Hertwig and Chun are considered by the author 

 to be poisoning thorns. — 3. The Histology and Nervous System of the 

 Calcareous Sponges. By R. von Lendenfeld, Ph.D. The new facts 

 mentioned by the aiithor relate chiefly to the structure of the spicules and 

 nervous system of Sponges. The spicules are invested by a mesodermal cu- 

 ticule extending over the protruding portion, outside of which there is a layer 

 of cells. The spicules themselves are composed of minute prisms. The 

 nervous system consists of mesodermal spindle-shappd sensitive elements 

 and multipolar ganglion cells. These are not present in the Asconidae and 

 Homodermidae (New Fam.). In Sycones they form rings or separate bunches 

 around the inhalent pores. In Lenco7i es they are either solitary or in bunches 

 scattered irregularly over the outer surface. Gland cells in HcterococUa are 

 described. — 4. Addenda to the Australian Hydromedusae, No. 2. By R. 

 von Lenden f eld, Ph.D. This paper treats of some recently established 



