246 
BULLETIN OF THE BUREAU OF FISHERIES. 
acted upon by McMurrich (vide supra), vrlio proposed its reference to the genus Eloaciis of Andres. 
This was later followed by Parker, and following these proposals I have formally accepted this refer- 
ence. At the same time it should be said that the grounds of the proposed reference to another genus 
are not altogether conclusive. Whether a given species be hexamerous or decamerous, in view of 
the range of variation now known to prevail to considerable extent, can hardly be of great significance 
as a taxonomic feature. While the species under consideration is apparently predominently decam- 
erous, I have found considerable variation in this respect. In younger specimens the hexamerous 
condition is not at all uncommon. In several different specimens some 50 to 70 mm. in length which 
I took occasion to section and examine the hexamerous state was prevalent. In very large specimens 
the decamerous arrangement was quite as prevalent. 
The general features of the species will be fairly well shown in figure 4, plate xlii. As will be 
seen, the body is elongated, more or less cylindrical, and comprises some three disting^uishable regions; 
An oral, retractile portion, or capitulum; a 
basal, bulbous portion, or pedal-like disk, 
or physa; and an intermediate portion, the 
column. This is marked by a series of 
about 20 longitudinal grooves, whose inter- 
mediate ridges are provided with numerous 
papilliform suckers, by means of which the 
creature is able to retain itself in the burrow. 
The length of the body varies greatly, aver- 
aging perhaps 100 to 150 mm. in ordinary 
life. In some cases at full extension it may 
become twice this length (Verrill). The 
diameter also varies greatly. It probably 
averages about 8 to 10 mm. The tentacles 
are normally 20 in number, with occasional 
variations, rather stout, with brownish knob- 
iike tips. The color varies from whitish to 
pale salmon on the column, the base trans- 
lucent, with bluish tint. A white variety 
has been described under the name Hal- 
campa alhida; but this is doubtless a merely 
varietal character, and in nowise entitled to 
specific distinction. 
Habitat: The species is characterized in 
a remarkable degree by the burrowing habit. 
In many years of observation I have never 
fotmd it except in burrows on sand flats 
between tide lines. In this habitat it forms burrows wherein it lives, perhaps more or less perma- 
nently. However, it should be said that specimens in the aquarium, in which, by the way, it will 
thrive for weeks in apparent vigor, yet show a tendency to emerge from the burrows at night and to 
migrate variously about tlie aquarium. A further fact may not be without some significance to the 
same effect, namely, that its burrows do not become lined by a tubular product, such as is provided 
by Cerianthus. I have elsewhere (Biological Bulletin, vol. xii, p. 274) pointed out certain peculiarities 
of behavior of some significance in this connection, and also as indicating something as to modes of 
life. That it is markedly sensitive to varying degrees of light, even to the extent of distinguishing 
between light and darkness, which has rendered the species predominantly nocturnal, seems to be 
beyond doubt. 
These two feattnes, namely, the burrowing and nocturnal habits, conspire to render its presence 
rmknown by most people, except those who especially direct attention to its discovery. While more 
abundant locally than either Sagartia modesta or Edwardsia elegans it is yet far from common. 
Fig. 
4 . — Tealia crassicornis. 
entoderm; m 
Section of circular muscle (c. w.); 
mesoderm; ec, ectoderm. 
