562 PROFESSOR E. P. WRIGHT ON THE TEREDIDE. 
tered perforations; end inclosed by two overlapping convex septa, arising from the sides 
and completely closing the ends. | 
These arched terminal plates appear to be absorbed before each period of activity, and 
the end is again closed with similar plates at each period of rest, after a sufficient elon- 
gation and enlargement of the tube for the protection of the enlarged animal, which lives 
sunk in sandy mud on the shores of tropical climates. 
These emended characters of Dr. Gray have been adopted by all recent writers on the 
subject. Thus Messrs. H. and A. Adams, in their important work ‘The Genera of Recent 
Mollusea,' pp. 331-648, regard the genera Teredo, Linn., and Kuphus, Guettard, as the two 
genera of the subfamily Teredininæ ; and Mr. Tryon, in his elaborate monograph of the 
family Teredidæ *, divides the family into three subfamilies :—I. Teredinæ, containing all 
the recent Teredines except Kuphus; II. Teredinidæ (fossil), and III. Kuphinæ, this 
latter characterized as “without valves, tube clavately cylindrical, sunk horizontally 
in sand, never penetrating timber ;" and suggests that Teredina may indicate a passage 
from the free and perfect valves of Teredo, through its less important valves eventually 
becoming merely a portion of the tube, to Kuphus, where the valves are wanting, or are 
replaced by the cleft shelly plate which closes the lower end. 
Mr. Tryon had very probably, at the time of reading this memoir, not seen a further 
paper by Dr. Gray in the * Proceedings of the Zoological Society of London' t, in which he 
points out the danger of arriving at conclusions on imperfect premises ; for he proceeds to 
describe two specimens of a large shell-bearing Teredo from some of the Dutch colonies 
of the Indian Ocean, that, so far as its palettes were concerned, bore a very close resem- 
blance to Furcella (Kuphus). The palettes of these specimens are described as being of 
precisely the same form and nearly of the same size as those figured } of Kuphus are- 
narius; but instead of having a small tubercle on the middle of the inner side of the 
dilated head, each palette is produced into an elongated process about half an inch long, 
which is more slender and oblong at the base, thicker, flattened, and dilated above, and 
truncated at the top. The valves closely resemble those of Teredo navalis, norvegica, 
and others, but are larger. Not wishing to pronounce positively that this animal belongs 
to the genus Furcella, Dr. Gray named it provisionally T. furcelloides. 
I am inclined to think, on a careful examination of these specimens, that this species 
of Dr. Gray is the same as, or at least very closely allied to, one described by Dr. 
A. A. Gould $ under the name Teredo thoracites, from Tavoy, British Burmah, and for 
which he afterwards made a new genus, Calobates ||. The palettes are very large and 
long, stilt-shaped ; the style long and subulate, slightly flexuous, bony, surrounded by à 
broad dilatation or step; concave on one side and convex on the other, its upper surface 
deeply excavated ; on this is placed the blade, which is three-fourths as long as the style, 
thin, linear, oblique, truncated at the tips, about one-third the width of the step. 
.* Proceedings of the Academy of Natural Sciences of Philadelphia, 1862, pp. 453-482. 
+ 1861, p. 313. 
t Proceedings of the Zoological Society, 1857, (Mollusca), plate xxxix. fig. 3. 
§ Proceedings of the Boston Society of Natural History, vol. vi. no. 6, October 1856, p. 15. 
| Tryon, loc. eit. p. 473. 
PP nl aa na PRO nn I na E E EE EAE EL Te NN ORNE eT Ee 
