CIBRIPEDIA. 285 



the inner basal lining of the sac extending a certain way upwards 

 around the sac. There are no true oviducts. In the Lepadoids the 

 ovaria have a more complex form and extended place : they consist, 

 on each side, of a thoracic and peduncular portion connected by a long 

 unbranched canal. The thoracic ovaria {Jig- 124,o), mistaken by Cuvier 

 for salivary glands, correspond in position with the entire ovaria in the 

 Balanoids : they are of an orange colour, and present the form of two 

 parallel, gut-shaped masses, having, in Otion, a great flexure, and 

 generally dividing at the end near the mouth into a few blunt 

 branches. Mr. Darwin, who has given the best account of the female 

 organs in the pedunculated Cirripeds, writes, " The state of these two 

 masses varied much ; sometimes they were hollow, with only their 

 walls spotted with a few cellulai' little masses ; at other times they 

 contained, or rather were formed of, more or less globular or finger- 

 shaped aggregations of pulpy matter ; and, lastly, the whole consisted 

 of separate pointed little balls, each with a large inner cell, and this 

 again with two or three included granules. These so closely re- 

 sembled, in general appearance and size, the ovigerms with their 

 germinal vesicles and spots which I have often seen at the first com- 

 mencement of the formation of the ova in the ovarian tubes in the 

 peduncle, that I cannot doubt that such is their nature."* The 

 connecting canals diverge at the bases of the first pair of limbs, bend 

 along each flank of the prosoma, under the superficial muscles, and 

 converge to penetrate the peduncle, along the ventral side of which 

 they run close together, and, when half-way towards the end, begin 

 to branch out in aU directions ; the ova being developed within the 

 stems of the branches as well as at their ends. " A minute point 

 first branches out from one of the tubes, its head enlarges like the 

 bud of a tulip on a footstalk ; becomes globular, shows traces of 

 dividing, and at last splits into three, four, or five egg-shaped balls, 

 which finally separate as perfect ova"f (^g- 121, i). 



According to the same author, the ova, immediately before one of 

 the periods of exuviation, burst forth from the ovarian tubes in the 

 peduncle, and round the sack of the animal, and, moving " along the 

 open circulatory channels, are collected (by means unknown to me) 

 beneath the chitine tunic of the sack, in the corium, which is at this 

 period remarkably spongy and full of cavities." The corium forms or 

 "resolves itself into the very delicate membrane separately enveloping 

 each ovum, and uniting them together into two lamellae : the corium 

 having thus far retreated, then forms, under the lamellae, the chitine 

 tunic of the sac, which will of course be of larger size than the last- 



• CCXXIII. p. 57. t CCXXIII. p. 57. 



