ZOOLOGY AND BOTANY. MICROSCOPY, ETC. 763 



Echinoporiiife, most of Duncan's Astrfeidae, and all the Litliophylliacese ; 

 while the Euthecalia compx-ise apparently all the genera of OculinidgB, 

 many if not all Turbinolidte, Eusmilinoe, and Euphylloidte. 



After a chapter on the nomenclature of coral structures, Dr, Ortmann 

 proceeds to discuss the formation of the coral stock or C()lon3'-, with 

 special reference to Fungia, which he regards " as a true stock with 

 division of labour such that in the centre there is situated a large, radiate 

 person with an oral apertiire, and round about this numerous smaller 

 individuals, of each of which only a tentacle persists." 



A discussion of the radiate symmetry and the development of septa 

 leads on to the question of the Tetracoralla, in regard to which Ortmann 

 urges (1) that there is no essential difference between them and Hexa- 

 coralla, (2) that bilateral corals are predominantly solitary forms, 

 (3) that since Palaeozoic times the bihxteral tj'pe has been on the wane, 

 and that in the development of the Hexacoralla the bilateralness is 

 pushed back to a very early embryonic stage, (4) that the Hexacoralla 

 have sprung directly from Tetracoralla. 



Milne-Edwards' law of the increase of the septa is modified into the 

 following : — In 6-radiate corals, the number of septa grows in such a 

 way that new septa arise througliout where there is room for them. If 

 a coral lias a more or less regular shape, then the new septa conform, 

 but always in the closest connection with the external form of the coral, 

 and directly explicable in relation to the same. 



The author thinks that twelve (certainly not six) is the fundamental 

 number for Hexacoralla, and finally sums up with a few modifications 

 his previously published conclusions on the general pedigree of the 

 Hexacoralla. 



Bunodes and Tealia.* — Messrs. G. Y. Dixon and A. F. Dixon have 

 some notes on Bunodes thallia, B. verrucosa, and Tealia crassicornis. 

 The first of these resembles Tealia hunodiformis in the possession of 

 " endodermal saccules," the form and arrangement of the mesenteries, 

 and the nature of the circular muscles. In order to ascertain the generic 

 and specific value of these characters the other two species were investi- 

 gated, and the conclusion was arrived at that if B. thallia and T. hunodi- 

 formis are not identical, they are at least more closely allied to each 

 other than to either of the two other forms with which they have been 

 compared. According to the jn-eseut systematic arrangement of Hertwig, 

 an adult Tealia crassiformis with its parts in multiples of five, an adult 

 Bunodes verrucosa with its parts in multiples of six, and an adult B. thallia 

 with no apparent numerical symmetry, are all relegated to the same 

 family. 



Edwardsia-Sta°^e in Free-swimming Embryos of a Hexactinian.f — 

 Mr. J. P. McMurrich, in studying some swimming embryos of Aulactinia 

 stelloides, found that they jjasscd through a stage with e:ght mesenteries, 

 the longitudinal muscles of which were arranged as in Ldivardsia. The 

 hexactinian arrangement is derived from this by the formation of the 

 fifth and sixth pairs of mesenteries, which make their appearance respec- 

 tively between the dorso-veutro-lateral and the ventro-lateral and ventral 

 directive mesenteries. 



* Soient. Froc. K. Dublin Soc. vi. (18S9) pp. 310-20 (2 pis.), 

 t Circ. John Hopkins Univ., viii. (1889) p. 31. 



