376 NOTKS ON SOME BniTIRII NT'DTRRANCIIS. 



The herina))hro(lite gland is very large, and fills the whole posterior 

 part of tlie body with lunaerous packets of yellowish-white follicles. 

 The anterior genital mass is enormous (10 mm. x 7 mm.) for the size of 

 the animal, and lioth the miicons and aUmmen glands are greatly 

 swollen. The si»erniatotheca is elliptical. The verge is as described 

 above; the canal follows the whole length of the flagellum to the 

 very end. 



It would seem that tlie Hagelliform character of the verge distinguishes 

 this species from J. hualinus. No such formation is indicated in Bergh's 

 description of J. hyalinus, nor have I found it myself in that aninial. 

 Also there seem to be some differences in the radula ; and though the 

 shape of the cerata is unfortunately unknown, the general appearance 

 and dead-white colouring do not resemble J, hyalinus. But the species 

 is open to doubt unless conlirmed by other specimens. 



ALDERIA, ALLMAN. 



Three species of this genus have been descril)ed. 



1. A. tiiudesta (Loven). 



2. A. comosa, A. Da Costa. Naples {Ann. del Museo Zoologico, Napoli, 



anno iv. 1864, p. 32, and pi. ii. 3). 



3. A. harvardiensis (Agassiz). East coast of North America (see 



Gould, Invertebrata of Massachusetts, 1870, pp. 254-5, pi. xvi. 

 226-8). 



Alder and Hancock published some account of the anatomy of 

 A. modesta in their monograph, but only the external features of the 

 other two species are known, A. comosa is green, with numerous long 

 cerata, and the anal papilla lies behind the pericardium. It must be 

 regarded as very doubtful if A. harvardiensis is really distinct from 

 A. modesta, whicli differs in being darker, in having fewer and smaller 

 cerata, and, if Gould's figure may be trusted, in the more angular shape 

 of the head. lUit the description and the figure do not quite agree as 

 to the disposition of the cerata, and the colour of A. modesta is very 

 variable. 



Alderia seems allied to Zimapontia, from which it differs chiefly in 

 having cerata and a much greater ramification of the hepatic system. 

 The lateral expansions of the foot n^uiind one of the wings of Elysia. 



ALDElilA MODEiSTA, LOVEN. 

 (Aloku and Hancock, Monog., Genus 17, Fam. 3, pi. 41.) 



I am indebted to Mr. W. I. Beaumont for several specimens of this 

 interesting form, labelled " Ardfry, County Galway, May 1904." In 

 some unpublisiied MSB. of Albany Hancock preserved in the Hancock 



