Miscellaneous. 215 



The spicules are straight slender bacilli, bearing obtuse spines on 

 two of their sides ; these are tolerably long and of the same diameter 

 as the bacillus itself. They are consequently very analogous in their 

 form to those of certain species of Cidaris, and especially to the 

 second of the forms represented in fig, 8 of the fifth plate of my 

 memoir on the Echinida. This figure represents various forms of 

 the spicules of a Bnsso2)sis from Mexico. In Ecliinoneus there is 

 merely a greater homogeneity of form. 



Thus the Echinonei, which in form and in the greater part of their 

 characters are intermediate between the regular Echinidae and the 

 Spatangoidae, are equally intermediate in the constitution of their 

 ambulacra. 



It is to be wished that those naturalists who possess irregular 

 Echinida in a good state of preservation would fill up the gaps which 

 I have been obliged to leave in my general work, at least if they 

 are convinced that the pedicellarise and ambulacra can furnish good 

 characters, as I believe I have shown to be the case. — Annales des 

 Sci. Nat. 5® ser. tome xiv. art. 5. 



On the Reproduction of the Lopliobmnclis, and on the Filiation of 

 certain Genera. By M. Canesteini. 



It is known that the males of these fishes, or at least of the 

 greater part of them, present cavities at the lower surface of the 

 tail, in the form of fossettes, or of sacs, in which the ova undergo 

 development, and in which the young remain for a certain time after 

 exclusion. M. Canestrini has not been able, any more than the ich- 

 thyologists who preceded him, to actually see the manner in which 

 the ova arrive in these receptacles ; nevertheless he gives a suffi- 

 ciently plausible hypothesis, based on certain anatomical arrange- 

 ments. He supposes a sort of coition, in which, contrary to what is 

 seen in other cases, the female products pass into the body of the 

 male. The position of the sexual orifice of the female and that of 

 the opening of the ovigerous sac would facilitate this. In fact the 

 female sexual orifice looks downwards, and the orifice of the ovigerous 

 sac is directed upwards, so that, if an" individual of each sex be 

 placed the one against the other, the female orifice will face the ori- 

 fice of the ovigerous sac and be able to discharge its ova into the 

 latter. It is probable that the prehensile tail of these animals also 

 plays a part (at least in the case of the Hippocampi) by enabling the 

 two individuals to hold each other closely united during this act, 

 which must last a certain time or else be repeated again and again. 

 The concourse of the sexes is evidently indispensable with the Ne~ 

 rophes, which have no pouch to receive the ova, but merely a series 

 of fossettes at the surface of the belly, so shallow that no ovum could 

 remain there if it were not deposited in its place and fixed by an ad- 

 hesive substance. 



M. Canestrini thinks that the male fecundates the ova after they 

 have entered the ovigerous sac, the male sexual opening communi- 

 cating with that cavity by means of a duct formed at the expense of 



