INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 731 



iu copulation tlie worms become covered with a thick opaque mucous 

 layer, which very effectually prevents observation ; an examination of 

 the efferent ducts and seminal vesicles did not reveal the presence in 

 them of anything like the spermatophores, which, it maybe observed, 

 are attached to ridge-like projections somewhere between the twenty- 

 fourth and twenty-ninth rings ; the ridges were found to be connected 

 with internal follicles, which were apparently setigerous, and about 

 three times as large as the other setigerous follicles of the neural 

 aspect of the worm. The setiB in question differed from the rest, not 

 only by their greater size, but by the fact that they did not project 

 beyond the surface. They are surrounded by a capsule of connective 

 tissue, in the walls of which there are, in addition to the matrix of 

 the setfe, some small glandular structures, very similar to those found 

 in the " capsulogenous glands." Varying somewhat in number, these 

 glandular tubes always lie between the hypodermis and the circular 

 layer of muscles ; they have not a wide lumen, and are generally 

 found to be filled with a firm coagulated secretion ; a branch from 

 this follicle passes into the sheath of the seta, where it ceases to be 

 glandular, and the epithelial cells become flattened ; the spermato- 

 phores are generally found between the orifices of the two glands, and 

 sometimes project into their ducts ; before copulation the spermato- 

 phoral tubes are soft, and contain no semen ; and finally, if they are 

 found on the twenty-sixth ring (in L. agricola) they would in 

 copulation be exactly opposite the male orifice of the other worm. 



The paper, which is illustrated by one plate, concludes with a 

 detailed list of the observations which were made. 



Body-cavity of the Sedentary Annelids and their Segmental 

 Organs.* — M. Cosmovici communicates the following to ' Comptes 

 Eendus ' : — 



The general body-cavity of the sedentary Annelids is divided 

 into several compartments by diaphragms, which sometimes exist 

 only in a portion of the cephalothoracic region (Arenicolce, Terehellce, 

 Cli/mcnice), sometimes throughout the length of the body (Serpu- 

 lida;) ; and then each segment has a cavity more or less inde- 

 l^endent of its neighbours. There are also divisions in the ojjposito 

 direction. In sections there are seen a central cavity filled by the 

 digestive tube, and two lateral ones separated from the former by 

 muscular bands in the form of oblique diaphragms. A communica- 

 tion exists between all the cavities through the interstices of the 

 fibres of the partitions. The lateral cavities contain the feet with 

 their retractor muscles and the segmental organs ; these are the pedal 

 cavities. 



In Chcetopterus pergamentaceus the arrangement of the cavities 

 in the three vesicular segments is interesting. The median cavity, 

 containing the digestive tube and the genital glands, does not com- 

 municate with the lateral cavities, which are occupied by the reno- 

 segmental organs, except by the segmental pavilion which opens in 

 the wall of separation. 



* 'Comptes Eendus,' Ixxxviii. (1879) p. 1092; 'Ann. anl Mog. Nut. Hist.,' 

 iv. (1879) p. 94. 



