224 CLASS vn. 



name Notospermus, which he gave to the worm examined by him. 

 The Nemertini appear, according to E.ATHKE and QUATREFAGES, to 

 have the sexes distinct, and the organs of propagation (testes, ovaria) 

 consist of blind saccules, which lie beneath the integument longitu- 

 dinally, upon the wide canal already described. There are three 

 blood-vessels running longitudinally, two on the sides and more 

 towards the ventral surface, and one on the dorsal surface, which 

 divides anteriorly into two branches which pass into the lateral 

 vessels. The nervous system consists of two head-ganglia united by 

 a transverse cord, from which (besides other nervous branches) two 

 very notable nerves arise, which run longitudinally backwards, 

 along the sides of the body. 



Compare for the anatomy of this family, besides OERSTED and the other 

 writers cited above, DELLE CHIAJE, Memorie n. pp. 406 409 and 427, 

 (extract by K. WAGNER in OKEN'S Isis, 1832, s. 555, 556, s. 647649) ; 

 HUSCHKE, OKEN'S Isis, 1830, s. 681 683, Tab. vn. figs, i 6; RATHKE, 

 Beitrdge zur vergl. Anat. u. PhysioL Danzig, 1842, s. 93 104 ; QUATRE- 

 FAGES, VInstitut, Journal universel, &c. No. 660, 1846, p. 286, and a figure 

 in the new illustrated edition of CUVIER, Regne Animal, Zoophytes, PI. 34 

 (and also a Memoire sur la famille des Nemertiens, Ann. des Sc. not. sieme 

 Serie, Tom. VI. Zool. pp. 173 303). 



Nemertes Cuv., Borlasia OKEN. Several eyes (often indistinct). 

 Two pits (respiratory?) at the sides of the head, surrounded with 

 vibratile cilia. 



Sp. Nemertes Borlasii, Borlasia Anglice OKEN, BORLASE, Nat. Hist, of 

 Cornwall, fol. 1758, PI. xxvi. fig. xiu. (cited by CUVIER), QUATREFAGES in 

 Cuv. R. Ani. e~dit. ill., Zuoph. PI. 33 ; this worm becomes more than four 

 feet long ; &c. 



. OERSTED cites as synonyms of this genus Notospermus 

 HUSCHKE, Meckelia LEUCK., Ophiocepkalus QUOY and GAIM. 



OERSTED has given the name Borlasia to species with constricted 

 head, without respiratory fissures, with indistinct eyes. Add several 

 genera, of which the synonyms cannot be made out except by com- 

 parison of the specimens : Cephalothrix OERST., Astemma OERST., 

 Tetrastemma EHRENB., Polia DELLE CHIAJE, Polystemma, Om- 

 matoplea, Amphiporus EHRENR., Cerebratulus RENIERI, Amphiporm 

 OERST. (not EHRENB.), Serpentaria GooDSiR 1 . 



1 Descriptions of some gigantic forms of invertebrate animals, Annals and Magazine 

 of Nat. Hist. Vol. xv. 1845, P- 37 7> P1 - xx - 



