6 Catalogue of Chaetopoda 



Insecta and Vermes distinguished by the number of chambers in 

 the heart and the nature of the blood, the first two classes with 

 " sanguine calido, rubro," the third and fourth " sanguine frigido, 

 rubro " and the last two " sanie frigida, albida." Insects were distin- 

 guished by the possession of antennae, Vermes by having " tentacula." 

 It follows from this mode of classification that any invertebrate not 

 having antennae, and therefore not referable to the class Insecta, 1 

 would fall into the class Vermes, which therefore necessarily became 

 a very heterogeneous assembly. In the twelfth edition (1766-8), 

 which was the last revised by Linnaeus, the class Vermes was 

 subdivided into seven orders Tardigrada, Imperfecta, Intestina, 

 Mollusca, Testacea, Lithophyta and Zoophyta only three of which 

 need be considered in this account. The genera were arranged under 

 these three orders in the following manner : 



VERMES INTESTINA, terrena quondam dicta, ob summam simplicitatem 

 corporis, terebrant omnia. Animalia simplicia, absque artubus, nuda. Lum- 

 bricus, Sipunculus, Fasciola, Gordius, Ascaris, Hirudo, Myxine. 



VEKMES MOLLUSCA, nuda, brachiata, vagantur pleraque per maria, 



Animalia simplicia, nuda (absque Testa inhabitata) artubus instructa. Actinia, 

 Ascidia, Limax, Aplysia, Doris, Tethis, Holothuria, Terebella, Triton, Sepia, 

 Clio, Lernaea, Scyllaea, Aphrodita, Nereis, Medusa, Asterias, Echinus. 



VERMES TESTACEA, mollusca, domiporta, calcareaque domuncula nobilitata 

 .... Animalia Mollusca simplicia, domo, saepius calcarea, propria obtecta. 

 Chiton, Lepas, Pholas, Mya, Solen, Tellina, Cardium, Mactra, Donax, Venus, 

 Spondylus, Chama, Area, Ostrea, Anomia, Mytilus, Pinna, Argonauta, 

 Nautilus, Conus, Cypraea, Bulla, Valuta, Buccinum, Stronibus, Murex, 

 Trochus, Turlo, Helix, Nerita, Haliotis, Patella, Dcntalium, Serpula, Teredo, 

 Sabella. 



It is evident from this commingling of worms and members of 

 other phyla that the work of previous naturalists and his own obser- 

 vations were not sufficient to indicate clearly to Linnaeus the 

 characteristic features of the worms which we now group together as 

 Annelids, the seven genera of which he placed in three different 

 classes, or even to enable him to separate worms from Mollusca and 

 Echinoderma. Linnaeus had, however, some conception of the 

 affinities of both Serpula and Sabella, for, after the name of the 

 former genus he added " Animal Terebella," and after the name of 

 the genus Sabella "Animal Nereis" (12th edition, pp. 1264, 1268), 

 and under the species Sabella alveolata he stated " Genus hoc multa 

 habefc communia cum Nereidibus sed & os & tentacula oris diver- 



1 In both the tenth and twelfth editions of the " Systema " (pp. 639, 1064, 

 respectively), Linnaeus placed Scolopendra marina in the class Insecta. In 

 the twelfth edition he stated that this animal was used as bait for herrings. 

 There can be no doubt that one or more species of Nereis were thus indicated. 



