90 KELLTAD^E. 



as far as we know, confined to this species and Kellia rubra ; 

 the third orifice in the mantle is a small sessile anal one. We 

 believe the water to aerate the branchiae enters by the pedal 

 fissure, and when used, is expelled therefrom ; it is possible 

 that the curious anterior tube, which is a continuation of the 

 mantle, may, in conjunction with the central opening, also 

 admit some water to the braiichise ; but we will observe on 

 this point by and by. 



On each side of the body there are a pair of narrow, symme- 

 trical, pale yellow, striated laminae, and correspondent pairs of 

 short, thick, strong, subtriangular, coarsely striated palpi ; the 

 liver is pale green, and in close connection with the ovarium, 

 which is a thin membranous sac full of ova in the genial 

 season. 



It is now proper to inquire into the probable uses of the 

 anterior anomalous tube. As there is no ostensible reason 

 why nature should have departed from her accustomed plan 

 to place that organ before, which in every other bivalve except 

 K. rubra and this is behind, we cannot rationally conceive 

 that this singular appendage is a special branchial tube, as the 

 pedal orifice is most ample for the entry and expulsion of the 

 aerating fluid; we therefore think the following facts will 

 afford malacologists assistance in determining its functions. 

 Whilst examining some K. suborbicularis, my attention was 

 suddenly attracted by observing several testaceous young 

 ejected from the anomalous tube; these I collected and have 

 them now by me. Notwithstanding tliis fact, I have never, 

 until lately, been able to discover, in any of the numerous 

 ovaria I have inspected, anything except ova in different 

 stages of advancement ; but it is exceedingly probable that the 

 shells I saw ejected may have been deposited in tliis tubular 

 appendage of the mantle, and there received the development 

 in which I found them. 



Since this was written, I have to state subsequent facts 

 resulting from the examination of a very large Kellia suborbi- 

 cularis. I placed it on the umbones, when it immediately 

 exserted and opened the tube ; by the aid of a powerful lens, 

 I counted at its fundus fifteen largely developed ova, and I 



