340 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Gould (1841) in his "Report on the Invertebrata of Massachusetts," 
again records Bofri/lhis stcUafus, and mentions the existence of other 
forms which had not been satisfactorily made out. 
Stimpson (1854) in his "Synopsis of the marine Invertebrata of 
Grand ^Nlanan, X. B.," records the occurrence in that locality of a 
compound ascidian "with the aspect of an Aplidium,'' which in all 
probability was Amarmicium glahnim Verrill, as well as of another 
which "approximated in character to the genus Boirylloidcs,'' and was 
probably really a member of that genus. He also mentions what he 
regarded as a species of Clavellina (see p. 343). 
Leidy (1855) described and figured Amaroucium peUucidittn from 
the Rhode Island coast, placing it, however, in a totally different group 
of animals and calling it Alcyonidmm f pelluciduni. 
Packard (1867) in his "View of the recent invertebrate fauna of 
Labrador," records a " Leptuclininn sp." and (under the name Didrm- 
nium roscum Sars) also Tefradidemninii alhidam (\'en"ill). 
Further additions to the list of species were not made until the year 
1871, when Professor A. E. Verrill published in the American Journal 
of Science a series of papers entitled "Descriptions of some imperfectly 
known and new ascidians from New England." In these he describes 
again the three species above mentioned as well as seven new ones, and 
figures a number of them. In these papers, he proposes three new 
genera, Macroclinum, Lissoclinum, and Lioclinum (see below, p. 384), 
and establishes apparently for the first time, the almost universally 
adopted families Botryllidae, Polyclinidae, and Didemnidae (Amer. 
Journ. Sci., ser. 3, vol. ] , p. 211). Later in the same year, in an article 
in the same journal, entitled "^On the distribution of marine animals 
on the southern coast of New England," two more compound ascidians 
are described. The papers subsecjuently published by ^'errill in the 
course of the aeneral investigation of the marine fauna of the New 
England region which was then being conducted by the United States 
Commission of Fish and Fisheries (now the Bureau of Fisheries), 
and especially the " Report upon the invertebrate animals of Mneyard 
Sound" by ^^errill and Smith, which appeared in 1873, give many 
facts regarding the distribution and habits of these species, and in the 
latter work many of them are again described. No additions are made 
to the list of species, save that the occurrence of another member of the 
Botryllidae is mentioned. 
Since that time the compound ascidians of this region have been 
