Miscellaneous, 409 



her natural position on the floor of the nest, and the male, pro- 

 ceeding in his turn to the eeiling, fecundates the eggs which she 

 has lixed there. This manoeuvre is repeated during an hour or two 

 until all tho ripe eggs have been ex])elled *, 



When the process of laying is completed the female abandons the 

 nuj)! ial domicile, never to return ; but the male remains and watches 

 over the eggs until the young arc hatched; for the small Crustacea 

 which abound on the sandy shores, and on which Gobius minutus 

 subsists (Cranf/o)i, Mi/sis), would eat the eggs were they not vigi- 

 lantly guarded by him. 



During the time that the develojjment of the young is proceeding 

 the male vibrates his tail and pectorals, so as to set up currents 

 under the shell, which ensure the renewal of the water in it. 



If after a male has made choice of a domicUe under a shell we 

 turn the concavity upwards, he restores it to its original position in 

 the following manner : — 



He begins by passing under the edge of the shell, rakes up the 

 sand about it if necessary, then placing himself at the side opposite 

 to the hinge, he nips one of the sides gently, and by a rapid move- 

 ment of his tail describes a semicircle in the surrounding water in 

 such manner as to swing round the shell till its concavity is under- 

 neath. Then he clears this at some point in its contour, and intro- 

 duces himself beneath ; he then throws out the superfluous sand in 

 the interior and covers it as has been described above. When the 

 male is guarding the clutch that he has fecundated the experiment 

 is still more certain of success. 



If we drive away a male from the nest he has prepared he is not 

 long in returning to it, even if other shells resembling hia own 

 are placed near his dwelling for the purpose of deceiving him. If 

 when a male is watching over the eggs which he has fecundated we 

 drive him away and replace his shell by another, leaving the first at 

 a little distance, when he returns he enters the shell which occupies 

 the position the first had without hesitation ; but he is not long in 

 perceiving that it does not contain his eggs ; then he quits it to 

 seek for and retake possession of the first. He does not scruple to 

 fight furiously if during the experiment another male has possessed 

 himself of the shell containing his offspring. — Comptes Rendus. 

 Aug. 10, 1891, p. 293. 



On the Excretory Apparatus of the Carididae, and on the Renal 

 Secretion of the Crustacea f. By M. P. Maechal. 



I. In a previous note I briefly described the excretory apparatus 

 of Palcemon. I have since examined a few other Carididie, which 

 exhibit, in this respect, certain important diff'erences. In Niha 

 edulis the labyrinth is wanting ; the gland is formed solely by the 



* To make the observations respecting the laying, instead of supplying 

 shells to the males I gave them watch-glasses, which I covered or un- 

 covered at will hv means of a brush. 



t The investigations were carried out at the Arago laboratory 

 (Banyuls-sur-Mer) . 



Ann. & Mag. N. Hist. Ser. 6. Vol. viii. 28 



