536 Miscellaneous. 



species of the allied geuus Cri/ptoniscus there is hermaphrodism 

 with successive functioning of the two sexes and protandn/. This 

 h5'pothesis, strongij- supported by the investigations of Bullar and 

 Paul Mayer upon the Cymothoadina, appears to me to be very 

 acceptable in the present state of our knowledge, and I willingly 

 extend it to the genera Hemioniscus and Entonlscus, and even to 

 other less abnormal Bopyrina, such as lone thoracica, which is also 

 found at AVimereux in the branchial cavity of Gallianassa siibter- 

 ranea. We should thus easily explain how, in the case of animals 

 so rare as the Entonisci, Fraisse and myself were able to find, com- 

 paratively often, upon the same crab, two or even three female 

 individuals in different stages of development and unaccompanied 

 by any male *. 



The young imperfectly developed females would in this case be 

 males, which, after having functioned as such, had succeeded in 

 attaching themselves directly upon the crab, and continued their 

 evolution as females, thanks to the more perfect nutrition which 

 they would obtain in their new position. The great dimensions of 

 the sac occupied by the Entonisciis leaves, after the escape of the 

 embryos, a free space much greater than in the case of the true 

 Bopyri, and facilitates this change of place of the male, the activity 

 of which is sufficient. 



SaccuUna Carcini is not very common at Wimereux ; the Ento- 

 niscus is very rare there. The coincidence of these two parasites 

 upon the same crab therefore possesses a real interest, especially 

 if we connect this observation with those made by Fritz Miiller upon 

 E. Porcelhuice, and by Fraisse upon E, Cavolinii. It is, it seems to 

 me, a fresh example of what I have called the mutual assistance or 

 the successive association of parasites in a determinate order, each 

 species preparing the soil for those which are to follow it. Demon- 

 strated first among the insects, this law seems to me to be of very 

 general application, and it will doubtless furnish valuable indica- 

 tions in comparative pathology when it is applied to parasites of a 

 lower grade, animal or vegetable. — Comptes Rendus, May 3, 1886, 

 p. 1034. 



Oti the Calcareous S2}onges of Minorca. 

 By M. Lakschewitz. 

 M. Lakschewitz has communicated to the Dorpat Society of 

 ^Naturalists a preliminary note on the calcareous sponges of Minorca, 

 founded upon collections made in 1882 by Prof. M. Brauu, chiefly 

 in the harbour of Mahon and the Alcanfa inlet. He adopts 

 Hackel's classification. 



Order CALCISPONGI^. 

 Fam. 1. AscoNES. 

 1. AsceU(( 2>rimorclialis, Hack. 

 Most of the specimens are flat cushion-like stocks of 10-40 millim, 

 * Fraisse found the Entormci upon seven fejiiales of Carcimis mcenas 

 without ova ; one of these crabs bore two and the other three parasites. 

 Upon a single Portunus imher I found two unequally developed specimens 

 of Entontscus Muniezii, the only individuals of this .species that I have 

 been able to observe. 



