426 REPORT ON /OOLOGY, MDCCCXLIV. 



connexion of the appendages ; genital aperture on the right side, on a level 

 with the eyes. Tongue cartilaginous, transverse, curved ; a ventricular sac, 

 from which proceed four branched trunks ; brain with four distinct ganglia. 

 A. vii-hlis, Okeu, and a new species, A. eleyans, have been observed. 



Actaeomn. Head distinct, notched anteriorly, widened by two thick 

 fringes, which posteriorly form two short tentacles, behind which are two 

 eyes ; body scarcely- broader than the head ; anus superior at the posterior 

 extremity ; branchial lobes thick, fleshy, forming a lateral fringe, and uniting 

 posteriorly ; foot very small, hardly reaching to the extremity of the body. 

 One species, A. senestro. 



Ampliorina. Head distinct, thicker than the body, with four tentacles ; 

 body flat ; foot longer posteriorly ; few branchial appendages, fusiform or 

 egg-shaped in two rows ; genital aperture on the right, anterior to the 

 branchial appendages ; two eyes behind the posterior tentacles ; two minute 

 lateral jaws and a tongue in the median line ; two intestinal sacculi, each of 

 which has its distinct opening in the oral cavity, large caeca penetrate into 

 the appendages of the body ; brain with two ganglia. One species, A. 

 Alberti. 



Pelta. Foot lateral and projecting posteriorly, not reaching the mouth, 

 head surrounded on the sides by two lamellar lobes, which unite posteriorly 

 in the middle ; no tentacles ; two eyes ; sides and posterior extremity of the 

 body separated by a groove ; tongue with a median and two lateral branches, 

 transverse ; stomach armed with four jaws, intestine saccular, pouches irre- 

 gular ; brain with two ganglia. One species, P. coronata. 



Chalidis. Body anteriorly and in the middle flat, in the posterior third 

 roundish, head distinct, instead of tentacles two broad lateral fringes ; foot 

 scarcely reaching to the mouth, indistinct posteriorly ; no special stomach, 

 the intestine consists of two long sacculi, united in the middle. Brain with 

 two ganglia. One species, Ch. ceerulea. 



All these animals are at most some lines long, and were observed on the 

 coast of Brittany. Their transparency facilitates the study of their anatomy. 



Souleyet (Comptes rendus, 19, p. 355 ; Annals xiv, p. 342) 

 comes forward to oppose the observations of Quatrefages. 

 He denies, in the first place, the absence of veins, the 

 existence of which he has proved by injection ; he has 

 traced them as far as the external branchial appendages, 

 from which he also proves that these appendages really 

 perform the respiratory function. Consequently, also, the 

 branches of the digestive canal, which frequently extend 

 into the branchiae, are not respiratory organs ; the author 



