Historical 7 



sissima ; " But the presence of the "test" evidently out- 

 weighed these many common characters, so that Sahella was not 

 placed near Nereis but among the shelled Mollusca. 



Gmelin, in his (the thirteenth) edition of the "Systema" (1788), 

 made no advance in regard to the separation of Worms from Mollusca. 

 The only changes from the twelfth edition which call for comment 

 here are — (1) the addition to the Vermes ^lollusca of the genera 

 Amphitrite Miiller, Spio Fabricius, and Nais Miiller ; and (2) the 

 removal of the species Scolopendra marina from the Insecta, and its 

 reduction to a synonym under Nereis versicolor and noctiluca. Gmelin 

 seems to have taken practically no notice of the suggestive work of 

 Pallas on Serpula (vide infra), for he still retained this worm among 

 the shelled Mollusca placed in the Vermes Testacea, and did not 

 adopt the improved arrangement of some of the worms suggested by 

 Miiller (see p. 8). 



Tlie stimulus given to the systematic study of animals by the 

 appearance of the " Systema Naturae " soon produced a marked 

 effect on the growth of knowledge in regard to the class of Vermes. 

 Observations on worms, in some cases accompanied by fairly adequate 

 descriptions of their characters, appeared in treatises of natural 

 history, in records of travel and in faunistic works, and there were 

 also accounts or memoirs pu])lished on single genera or species. 

 Seba ^ figured Millepeda marina [two nereidiform worms], Eruca sen 

 Scolopendra marina \Apliroditc\ Penicillum mariiium [a Sabellid] 

 and a cluster of slender worm tubes. Baster^ prepared a series 

 of plates with good figures of the external characters of Nereids, 

 " Scolopendi'ae plumosae " [Sabellids], Serpulae [including a frag- 

 ment of a Lanice and its tube], " Hirndo piscium" [Pontobdella^, 

 Aphrodita acidcata, A. squamata [a Polynoid] and Nereis pelagica ; 

 in the case of the last three some details of the feet were given. 

 Pennant's "British Zoology" (vol. IV, 1777) contains figures of 

 Lumhricus marinns, terrcsiris and minor, leeches, a Sipunculid, 

 Aphroditidae and Polynoids, Nereids and the tubes of Serpula and 

 Spirorhis. 



Pallas"" puldishod in 1776 an account of his admirable researches 

 on the anatomy, both external and internal, of Aphrodita [including 

 under this name Aphrodite, Polynoids and Amphinomids], Nereis 



' Locupl. lleium Nat. Thes. i, Anistelaedami (1734), tab. Ixxxi, 7, 8 : 

 tab. xc, 1-3 ; iii (1758), tab. iv, 7, 8: tab. xvi, 7a, 7b: tab. c. 8. 



- Op. Subseciva, i, Harlemi (1759-60), tab. iv, v, ix, x ; ii (1765), tab. vi. 

 •* Miscell. Zool., Hagae Comitiuiu (1766), tab. vii-xi. 



