Genus 16. HERIVLEA, Lov£n. 



Corpus elongatum, postice attenuatum, non palliatum. Caput terminale. Tentacula 2, auriformia, 

 extus canaliculata. Maxillae nullse. Branchice elongatse, papillosee, ad latera dorsi dispositse. Anus 

 anticus in medio dorsi situs. Orificium generationis laterale pone tentaculum dextrum. 



The interesting little mollusks on which this genus is founded, are distinguished from 

 their allies by the peculiar form of their tentacles, which are ear-shaped, reminding us, in this 

 respect, of Mysia and Aplysia among the naked mollusks, and of the family of Pyramidellida 

 among the testaceous tribes. With the last-mentioned genus, the relationship can only be 

 considered one of analogy; their affinity with the first may be further traced in the numerous 

 branchings, in close connexion with the skin, of the hepatic organ, and in the bilateral dis- 

 position of the principal trunks ; the great central canal having disappeared. And, indeed, 

 in this latter respect, all the members of the Pellibranchiata, an order recently proposed by 

 us, agree with this genus : and some of them so nearly resemble Hermaa dendritica in general 

 form, that, were its branchial papillae removed, it might be placed along with them. The 

 genus was established by Professor Loven in the Proceedings of the Royal Swedish Academy 

 for 1844. Its nearest ally is the Stiliger of Ehrenberg, from which it differs in the form of 

 the tentacles ; these organs in Stiliger being long, linear, and tapering. The Calliopcea 

 of D'Orbigny is another allied genus, if, indeed, it is not synonymous with the last, which we 

 strongly suspect to be the case ; but as the position of the anus, a material point in the 

 division of the genera, is left unnoticed by M. D'Orbigny, in his description of Calliopcea, and 

 as he considers the tentacles to be oral, no correct conclusion can be come to, until the species 

 he founded it upon shall have been re-examined. 



Not more than two or three species of Hermeea have been noticed, and these are confined 

 to the European seas, having hitherto been found only in the British Islands and in Norway. 

 They live in shallow water, are gregarious in their habits, and appear to be vegetable feeders, 

 though probably not exclusively so, as M. Loven has found H. bifida on Tubularice. Their 

 motions are quick and lively, and their power of extension and contraction remarkably great. 



The body of Herman, is generally slender, and either linear or ovate-oblong, terminating 

 posteriorly in a slender pointed, tail. There is no cloak, but sometimes the sides of the 

 body are a little produced, and overhang the margins of the foot. The head is terminal, and 

 occasionally slightly marginated in front, giving it a subvelar aspect. The mouth is inferior, 

 and not provided with corneous jaws : the tongue is slender and denticulated. The tentacles 

 are two in number, placed dorsally, and longitudinally folded or ear-shaped. The branchiae 

 are oblong or ovate papillae clothing the sides of the back. The anus is dorsal, placed far 

 forward on the median line and in front of the heart : it is usually tubular. The aperture of 

 the genital organs is placed below and a little behind the right tentacle. The foot is narrow 

 and linear. 



