50 COERESPONDENCE. 



myself, who would be glad of a little help in this portion of their 

 studies ; a help which there are many well qualified to give, who would, 

 I doubt not, be glad to give it, when they know that the desire for it 

 exists. — Neo-Mickoscopicus. 



CoNCHOLOGT. — During a geological excursion of the Natural Science 

 Section of the Nottingham Literary and Philosophical Society, I found 

 Helix cantiana, together with Helix ericetorum, on the sides of a railway 

 cutting, in the Great Oolite Limestone, at Kiugscliffe, Northamptonshire. 

 The cutting is on the new line being made between Melton Mowbray and 

 Kettering. I do not know whether it has been noticed in that neighbourhood 

 before. — At Easter, 1876, 1 found (during a walk from North Rode, Cheshire, 

 across the hills to Buxton) some dozen or more specimens of Limncea 

 truncatula, in a pond. They were, as far as I could see, its only living 

 occupants. The sides and bottom of the pond were coated with a 

 yellowish rusty matter, which looked like oxide of iron. I thought the 

 fact rather remarkable. During the early part of 1877 I found just the 

 same thing occurring in a pond by the road side, about a mile out of 

 Mansfield on the way to Ed-niustowe. But in this case, there was no 

 rusty deposit. Again, close to Nottingham, this same moUusk occurs in 

 a ditch, along with Phijsa lujpnorum (plentiful) and a small Fi.iidium, and 

 very rarely indeed Limncea ijere^ra (the spire of the latter being much 

 elongated, and finely tapered, and the body whorl of the shell smaller 

 than is usual.) Is it customary to find this mollusk (Limncea truncatula) 

 unassociated with any other species? Perhaps some of your readers 

 could inform me. In none of the cases was it plentiful. — C. T. M., 

 Nottingham. 



VoLvox Globator. — On a hill, near Eedditch, are two ponds, some 

 300 yards apart, the overflow of the upper of which I'uns into the lower. 

 On Christmas-day, 1875, Volvox (ilobutor was found in extraordinary 

 profusion in the lower x^ond, where it continued in abundance during the 

 following Januarj', but soon after disappeared. In the upper pond, 

 though at no time so numerous, specimens were found as late as March. 

 Search was made for them frequently during the remainder of the year 

 without success. As it appeared to the writer remarkable that they 

 should occur in such numbers in the winter, he was induced to examine 

 both ponds on Christmas-day, 187(5, and on several occasions during 

 Januaiy and February, 1877, but not a Voix'ox was visible. Nor did any 

 put in an appearance till July, when they were observed in the upper 

 pond only, though subsequently they were sparingly met with in the 

 lower. Incessant rain during the winter months bad made the water 

 veiy turbid, and possibly this state of things did not favour their develop- 

 ment. On the 6th Januai-y, 1878, Volvox was again found in considei-able 

 numbers, though not in profusion, in the upper pond, nearly all the 

 specimens being young. They continue to flourish, and with them occur 

 abundance of that beautiful rotifer Conochilus volvox^ which has been 

 constant in that pond throughout the year. — S. S. E., Redditch. 



London Notes by ax Occasional Correspondent. — Sucli of us, and we 

 ■were a larger audience than usual, as attended the meeting of the 

 Linnean Society, on January 17th, had a great treat in hearing and seeing 

 Professor Owen and Dr. Darwin, both, in consequence of feeble health 

 and advancing years, being very rare visitors on one evening to the learned 

 societies. The Professor's paper on a missing link (just fonnd) between the 

 existing Marsupials and some early forms of (now) fossil life, was of great 

 importance, but too tcclmical for its scope to be indicated in a paragi'aph. 

 Mr. Francis Dai-win, a most worthy follower in tlie steps of his great 

 father, read a paper on the results ot feeding Droscra rotundifolia, wliich 

 sets at rest the question of digestion and absorption in plants. After 



