Miscellaneous. 103 



different situations, we see that, under water, its cutaneous projec- 

 tions become more prominent and the pulmonary orifice closes ; in 

 the air, on the contrary, especially in freedom, and in dry weather 

 and high wind, the projections seem to disappear, the skin is almost 

 smooth, with small distant spines, whilst the pulmonary orifice is 

 widely opened beneath the raised margin of the mantle. In aquaria 

 the Oncidium seems to live indifferently in the air or in water ; very 

 frequently one sees the anterior part immersed, whilst the caudal 

 extremity is out of the water and the pulmonary orifice open. 



The foot presents a cavity which communicates with the exterior 

 by an orifice situated as usual, below and behind the mouth, near 

 two great muscular masses which the animal seems to employ' in the 

 fashion of two supplementary tentacles, and which are perhaps the 

 analogues of the small tentacles of the quadritentaculate jiulmonate 

 Gasteropods. By this cavity it is easy to inject the venous lacunae ; 

 and, with very penetrating injections of carmine or oxalic Prussian 

 blue, we may even fill the heart and a great part of the arterial 

 system. 



The genital apparatus, which is simpler, at least as regards the 

 male portion, than in the species studied by Cuvier and Keferstein, 

 is constructed upon the ordinary type of that of the monoecious 

 Gasteropods. The female apparatus includes a large hermaphrodite 

 gland with its coiled excretory canal, a vitellogene (albumen-gland 

 of authors), a matrix, which can be distinguished from the preceding 

 organ only in the fresh state, and which is continued into a canal 

 to which it will be best to reserve the name of the oviduct ; at 

 the points where this must be designated the vagina there are 

 inserted on the one side the canal of the copulatory pouch, and on 

 the other a vaginal prostate formed of a long tube swelled into a 

 clavate form. The female orifice is situated just in front of the 

 anus. In the male apparatus the deferent canal, properly so called, 

 runs directly to the side of the female orifice, and, as has been very 

 well observed, is continued into a channel situated on the right side 

 of the foot, and which extends to its anterior part, close to the 

 corresponding subbuccal muscular mass. Here this channel opens 

 at an orifice leading into a long tube folded upon itself, which must 

 be regarded as a seminal reservoir ; this tube finally terminates in a 

 hoUow muscular inflation, which is nothing but the invaginated 

 penis (sheath of the penis of authors) ; the orifice by which this 

 organ issues is situated in front of and close to the termination of the 

 deferent channel. Thus we see that the spermatic fluid, after having 

 traversed the deferent canal properly so called, must follow the 

 deferent channel in order to enter afresh into the interior of the 

 body, in the seminal receptacle. The copiilation is reciprocal ; the two 

 individuals are placed side by side in opposite directions, adhering 

 by the foot and the left portion of the mantle, the right portion 

 being raised to expose the genital orifices. I have observed these 

 animals coupled at two very diff'erent seasons, namely March and 

 October. 



To sum up, Oncidium ceUicum undoubtedly approaches the pulmo- 

 nate Gasteropoda, among which it is very properly placed ; never- 



