224 CLASS VII. 
name Motospermus, which he gave to the worm examined by him. 
The Nemertini appear, according to RaTHKEe 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 OkRSTED and the other 
writers cited above, DELLE CutasE, Memorie 11. pp. 406—409 and 427, 
(extract by R. WAGNER in OKEN’S Jsis, 1832, 8. 555, 556, 8.647—649) ; 
Huscuke, OKEN’s Jsis, 1830, s. 681—683, Tab. vit. figs. 1—6; RaATHKE, 
Beitrdge zur vergl. Anat. u. Physiol. Danzig, 1842, s. 93—104 ; QUATRE- 
FAGES, l'Institut, Journal universel, &c. No. 660, 1846, p. 286, and a figure 
in the new illustrated edition of Cuvier, Régne Animal, Zoophytes, Pl. 34 
(and also a Mémoire sur la famille des Némertiens, Ann. des Sc. nat. 3ieme 
Série, 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, Boruase, Nat. Hist. of 
Cornwall, fol. 1758, Pl. Xxvi. fig. x111, (cited by CuvIER), QUATREFAGES in 
Cuv. R. Ani. édit. il., Zvoph. Pl. 33 ; this worm becomes more than four 
feet long ; &e. 
Note-—OrrsTED cites as synonyms of this genus Motospermus 
Huscuxe, Meckelia Leucn., Ophiocephalus Quoy and Gam. 
OeERSTED has given the name Lorlasia 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 Oxrst., Astemma OERST., 
Tetrastemma ExRENB., Polia DELLE CutAse, Polystemma, Om- 
matoplea, Amphiporus EnRENR., Cerebratulus RenrEert, Amphiporus 
Orrst. (not EnReEns.), Serpentaria Goopsir’. 
1 Descriptions of some gigantic forms of invertebrate animals, Annals and Magazine 
of Nat. Hist. Vol. Xv. 1845, p. 377, Pl. Xx. 
