Monthy Microscopical] PROGRESS OF MICROSCOPICAL SCIENCE. 163 
their affinity with the worms. Lacaze-Duthiers figures the embryo of 
Thecidium, and it is a little animal with four segments. Fritz Miiller 
figures an early stage of Discina, and we have recalled to us a positive 
articulate and worm-like character. From the body of this embryo 
prominent bristles project. Smitt figures the same in the embryo of 
Lepralia, wherein he describes six bristles that appear locomotive ; 
and Claparéde figures the embryo of Nerine, a worm, in which we find 
similar bristles projecting from the body. In this connection it is 
interesting to note that in the winter eggs, or statoblasts, of Polyzoa 
we have a relation to similar characters among the lower crustacea, 
the ephippia of Daphnia and the winter eggs of Rotifers for example. 
Leuckart places the Polyzoa with the worms, and the close affinity 
of the Polyzoa with the Brachiopoda is now freely admitted, and we 
now recall those peculiar worms, or early stages of them, which so 
strongly resemble in almost every essential point of their structure 
the hippocrepian Polyzoa. As many of the foregoing points need 
ample illustration, and as the writer has in preparation a memoir on 
the subject, he will now only call attention to the facts supporting 
these views, evolved from the study of living Lingule. It is but 
justice to state that six months previous to the observations made on 
Lingula, he had come to conclusions herein expressed, and had freely 
argued it with his colaborators. He saw the necessity of examining 
Lingula, however, before advancing these views, and for this sole 
purpose had visited North Carolina in company with Dr. A. §. 
Packard, jun., who with his observations on the worms and crustacea 
of that region yet found time to follow the writer, step by step, in his 
studies of Lingula, and was deeply impressed by the disclosures there 
made. His sincerest gratitude is due to Dr. Elliott Coues, U.S.A., 
and Major Joseph Stewart, U.S.A., commandant at Fort Macon, North 
Carolina, for their constant aid and sympathy in furtherance of the 
object of his visit there. After nearly a week’s fruitless search, 
Lingule were found in a sand shoal, left at low tide. They were 
found buried in the sand. The peduncle, which was about six times 
the length of the shell, being encased in a sand tube differing in no 
respect from the sand tubes of neighbouring annelids. In many 
instances the peduncle was broken in sifting them from the sand, yet 
the wound was quickly healed and a new sand-tube promptly formed. 
When placed on the surface of the sand they were noticed to move 
quite freely, by the sliding motion, in all directions, of the dorsal and 
ventral plates, aided at the same time by the rows of setz or bristles, 
which swung back and forth like a galley of oars, leaving a peculiar 
track in the sand. The peduncle was hollow, and the blood could be 
seen coursing back and forth in its channel. It was distinctly and 
regularly ringed, and presented a remarkably worm-like appearance, 
Tt had layers of circular and longitudinal muscular fibre, and coiled 
itself in numerous folds or unwound at full length. It was contrae- 
tile, also, and quickly jerked the body beneath the sand when alarmed. 
But the most startling discovery in connection with this interesting 
animal was the fact that its blood was red. This was strongly marked 
in the gills, which were found in the shape of a series of rows of 
