276 THE AMERICAN MONTHLY [December, 



head ; it remained a quiet rounded mass at the foot of the mother 

 for about fifteen minutes, and then quite suddenly it swam around 

 and took its place in the colony. In this, as also in a second egg, 

 I could see no trace of an eggshell, but the difficulty of understand- 

 ing how the young is born quite free, could remain folded together 

 in the manner it did, even for a short period, made me watch a 

 third ego; with greater care, and this time I succeeded in making 

 out an exceedingly thin, transparent, soft membrane covering the 

 egg, totally unlike the thick chitinous eggshell we are accustomed 

 to find in other Rotifers. When the young had emerged I could, 

 with the best optical means, barely distinguish the outline of the 

 collapsed membrane. Although, therefore, C. unicoi-nis can- 

 not, strictly speaking, be said to be viviparous, it comes very near 

 to it. 



In several colonies I found ephippial or so-called winter eggs; 

 they are of the same size as the mature female egg (about i-330th 

 of an inch long), white, opaque, with a double shell ; the inner 

 shell is thick, granular, and has a tree-branch pattern on its sur- 

 face, but no spines or scales ; a distinct single ridge runs in an 

 oblique direction all round the inner shell. The outer shell is 

 thin, smooth, transparent. I also found some small mature male 

 eggs, both in utero and lying at the foot of the mother, and then 

 the male (Fig. 6), which is a small pear-shaped creature with a 

 small ciliated head and a large wreath of cilia just below on a 

 wider shoulder ; two red eyes in the head are conspicuous ; the 

 body cavity is wholly taken up with the sperm sac, and the pointed 

 low-er end is ciliated as usual. 



The specific characters maybe summarized thus : Clusters more 

 or less unsymmetrical, consisting of few (2-25) individuals; fused 

 gelatinous tubes distinct; ventral antennae joined together within 

 a single sheath on the surface of the corona, large and conspicu- 

 ous. Size of individuals i-ioo to 1-130 inch, of clusters 1-45 to 

 1-65 inch in diameter, male about 1-400 inch. Habitat, Keston, 

 England. 



Euchlanis parva. — This small but very attractive Euchlanis 

 (Fig. 5) I have found on two occasions, the last time being at 

 Keston. It can at once be recognized by its small size compared 

 with that of its congeners, being only 1-130 inch in length, while 

 all the other species of the genus are double the size and larger, 

 1-40 to 1-70 inch. The lorica is egg-shaped, of glassy transpar- 

 ency ; the dorsal plate is arched, having a broad rounded notch 

 anteriorly and a narrow notch behind. The ventral plate is much 

 smaller and flat. The dorsal occipital edge of the lorica is ex- 

 tremely thin and transparent, and the broad notch can therefore 

 only be well seen when the head is completely retracted. 



The internal anatomy is normal ; the brain is large and carries 

 a red eye in front of the mastax ; the lateral antennae are quite con- 

 spicuous and protrude through the dorsal plate in the lumbar re- 

 gion on each side. In the other, larger species these are visible 



