412 Messrs. Alder and Hancock on a 'proposed New Order 
appearance of the sperraatheca. Further than this, these organs 
seem to have escaped observation. 
In Cenia and Acteonia we have not been able to investigate 
the reproductive organs ; they both, however, have the intro- 
mittent organ provided with a curved crystalline spur- like point. 
The generative system of Actceon {Elysia), as given by Pro- 
fessor Allman, appears to have a considerable resemblance to that 
of Limapontia. We think we can recognise the same parts, 
though Professor Allman differs from us in assigning to them 
their various functions. To arrive at a just conclusion on this 
difficult subject, it is necessary, in the first place, to ascertain the 
position of the external orifices, and their connexion with the 
several parts of these complicated organs. Unfortunately in 
Actceon these points could not be determined. In Limapontia, 
on the contrary, we have had the good fortune to succeed in 
making them out with sufficient certainty ; consequently we have 
been able to speak with more confidence than we should have 
otherwise done. The large irregularly -formed organ in Actceon, 
which is designated testis, is undoubtedly the same that we con- 
sider the mucous gland. The opening of the gland externally, 
and the detection of eggs in the anterior portion of it and in its 
channel, are sufficient to prove that this cannot be the male 
secreting organ. If then this be the mucous gland in Actceon, 
the testis must be sought for elsewhere. It seems to have escaped 
notice. The vas deferens, however, has been traced backwards 
until it bifurcates near the median line of the body in the same 
way as it does in Limapontia. Here, therefore, judging from 
analogy, the testis begins ; and it will probably be found occu- 
pying a position in the neighbourhood of the ovary. The oval 
pouch [y] is most likely the homologue of the dilated portion of 
the common oviduct, and the small tube that passes from it 
backwards, dividing dichotomously, will prove, very probably, to 
lead from the ovarium. The oval body {x), we would surmise, 
corresponds with the dilated portion of the copulatory channel at 
the base of the spermatheca ; like it, it is in communication with 
the vas deferens, or testis, and with the oviduct ; and, if this con- 
jecture be correct, it will also communicate with the oval sac 
wdiich we take to be the spermatheca : it will likewise have an 
external outlet. 
From the description we have given of the reproductive system 
of Limapontia, it is evident that it does not differ in any material 
degree from what has been observed in the Nudibranchs. 
The ovary and testis are certainly considerably modified, and 
are differently arranged in the body ; their ducts, however, and 
the duct from the spermatheca, as in Eolis, ai’e all brought 
