Mr. F. Walker’s Descriptions of Aphides. 295 
mantle, one for the foot, and one in common, for branchiz and 
anus. teva 
It must not be supposed that I have mistaken the functions 
of this fissure, and that it only belongs to the anal apparatus. 
This is not the case; it is beyond doubt a common cavity for two 
distinct purposes, viz. anal and branchial. 
Thus this apparently strangely-formed animal turns out to be 
very similar to most of the bivalves, having the branchial and anal 
openings close together, where they ought to be, at the posterior 
end, and the anterior tube-like fold being nothing more than an 
aid to the foot in locomotion. I should not be at all surprised if 
the tube of Kellia suborbicularis, when closely examined (as it 
shall be), turns out to be an open canal; but whether this is the 
case or not, it is not for branchial, but locomotive uses. 
From this examination it results, that the only essential dif- 
ference between the two species is, that the one is viviparous and 
the other oviparous. You will now be able to judge if the genus 
Poronia must be adopted. 
In the twelve specimens no young were found, as in the summer- 
time; I therefore conclude that “ Alma Venus,” as Lucretius 
_ styles the goddess, does not influence the self-sufficing loves of 
these mollusca until 
peer ws *‘ species patefacta est verna diei, 
Et reserata viget genitabilis aura Favont.” 
I am, my dear Sir, most truly yours, 
Ed. Forbes, Esq. WititaMm Crark. 
XXXV.—Descriptions of Aphides. By Francis Waker, F.L.S. 
[Continued from p. 53.] 
61. Aphis Ribis. 
Aphis Ribis, Linn. Syst. Nat. i. 733. 1; Faun. Suec. 975 ; 
Gmel. ed. Syst. Nat. i. 2201; Fabr. Syst. Ent. 734.5 ; Sp. Ins. ii. 
385 ; Ent. Syst. iv. 211. 7; Syst. Rhyn. 295. 7 ; Frisch, Ins. ii. 
9. t. 14; Réaum. Ins. ii. 281-350. t. 22. f. 7-10; Hausm. IIl. 
Mag. i. 437. 2; Leuwenh. Arc. ep. 90. 545. t. 548; Blanck. Ins. 
164. t. 14. f. D. 2; Schrank, Faun. Boie. ui. 1. 108. 1195; Sir 
“<ite Mosley, Gard. Chron. i. 628; Kalt. Mon. Pflan. i. 39. 
Ribifex, Amyot, Ann. Soc. Ent. 2™ série, v. 476. 
This Aphis feeds on Ribis rubrum, R. nigrum, R. alpinum, R. 
grossularia, and R. uva crispa, from March till November. 
The viviparous wingless female. In the spring and when very 
young it is dark olive-green, oval, short, and plump: the feelers 
