Miscellaneous. 365 



arities are of two kinds : — first, the annelid grovrth has determined 

 outgrowth of the coral which has covered in the worm-tube ; and 

 second, the establishment of some Hydrozoa on the ectoderm of 

 the coral has sometimes produced the formation of tubes of coral- 

 structure which environ the stalk of the offender and form a 

 useful support to it. 



Finally it ma}'- be remarked that all the Madreporaria which 

 were brought up with the cable from off this area have an un- 

 usual ornamentation. 



I have to thank Sir James Anderson for the specimens and 

 for the details of the recovery of the cable. 



MISCELLANEOUS. 

 On some Points in the Embryology of Annelids. By M. C. Baerois. 



TiTE investigations, of which I now give a summary,^ were made 

 in the years 1873-7fi, and completed during the present year. 



The first fact relates to the discovery of a new type, common at 

 Eoscoff during the month of April, which must be referred to the 

 interesting group of the Gastrotricha. It possesses the form and 

 general aspect of the Ichthydinse ; but its skin is divided superficially 

 into several segments furnished with incomplete ciliary circlets, 

 which cause it to resemble the larva of an annelid. The digestive 

 tube consists of three divisions, of which the first bears a very 

 characteristic musciolar pharyngeal inflation, which I have also 

 met with in a small Syllidian, Nei-illa antennata. The specimens 

 were in full reproduction at the period when I collected them ; the 

 genital oi'gans form a series of glands, as in the llhabdocoeli. The 

 sexes are separate : the males possess two testes, situated one to 

 the right, the other to the left of the stomach, and which are fol- 

 lowed by two seminal vesicles which pass to a single penis ; the 

 female organs consist of two great masses, situated at the same part 

 as the testes of the male ; and these ovarian masses, like the testes, 

 are separated by a sort of dissepiment which divides the. body of 

 the animal into two parts. 



Copulation occurs ; then the ova are deposited ; and in order to 

 study them it is only necessary to collect them at the bottom of the 

 vessel. The segmentation is like that of annelids generally : a gas- 

 trula is formed byepibolism ; then the internal mass is concentrated 

 behind, while the anterior part becomes clear and the ventral sur- 

 face thickens into an embryonic band ; the posterior fatty mass 

 will form the stomach, the clear anterior part the oesophagus, and 

 the embryonic band the muscular layer. The latter, the investi- 

 gation of which would possess special interest, represents the 



