[McMURRICH] THE ACTINIARIA OF PASSAMAQUODDY BAY 73 
pinnate manner. In the only large individual in which the distribution 
of the reproductive cells could be determined with certainty, these 
structures were confined to the mesenteries of the youngest cycle, none 
occurring on any of the perfect mesenteries. 
* 
I have described the anatomical features of these individuals with 
some detail on account of the uncertainty of the status of the species to 
which I have referred them. They are certainly identical with the form 
for which L. Agassiz (1847) proposed the name Rhodactinia Davisit and 
which was later described by Verrill (1864), under that name. They 
are also identical with the form described by Stimpson (1853) as Actinia 
obtruncata. Of these two names that proposed by Agassiz has the 
priority, but in 1866 Verrill noted that the species was probably identical 
with the Tealia crassicornis of Gosse, a form originally named by O. F. 
Müller (1776). This identification has been generally accepted, with 
the exception that the fourth variety of the species recognized by Verrill 
in his original description was subsequently (Verrill, 1899), identified 
with Stimpson’s A. carneola, which will be discussed later. 
In 1902, however, Carlgren, basing his conclusions on the study of a 
large number of examples of so-called crassicornis, claimed that three 
distinct forms had been confused in that species, two of them, indeed, 
really belonging to a distinct genus. He proposes to restrict the term 
crassicornis to the more northerly European forms, and with these he 
identifies Agassiz Rh. davisti and also Act. elegantissima and A. laurentii 
of Brandt (1835) and Letotealia spitzbergensis of Kwietniewski (1898), 
referring the species to the genus Rhodactinia. The other two species 
are the Act. coriacea of Cuvier (1798) and Madoniactis lofotensis of 
Danielssen (1890) pro parte, both these forms being assigned to a genus 
for which the term Tealia, originally proposed by Gosse (1858), is appro- 
priated. On comparing the definitions of the two genera as given by 
Carlgren one notices only the following differences. In Rhodactinia 
the verrucæ of the column wall are described as “schwach unbedeu- 
tend,” while in Tealia they vary from “gut bis schwach entwickelt”’; 
in Rhodactinia the radial musculature of the disk and the longitudinal 
musculature of the tentacles are “meso-ectodermal bis mesoglceal” 
while in Tealia they are “uberwiegend mesoglceal”’; in Rhodactinia all 
the mesenteries are fertile with the exception of the directives, while in 
Tealia ten to twenty of the older pairs are sterile; and in Rhodactinia 
the development of the embryos is always (?) in the ccelenteron of the 
parent, while in Tealia it is always outside the body. 
If all these peculiarities were definite it might seem advisable to 
accept Carlgren’s conclusion, but, as is indeed to some extent indicated 
in his definitions, the features selected as distinguishing the two genera 
are very variable and therefore hardly reliable for the decided distinc- 
Sec. IV., 1910. 5. 
