Walton, L. B.

The Ohio Journal of Science

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A LAND PLANARIAN WITH AN ABNORMAL NUMBEROF EYES.L. B. WALTON.The land planarians which are relatively common in thetropical regions have few representatives in the temperate zones,only two species thus far being known from America north ofMexico, with the exception of the introduced form, Placocephaluskewense (Moseley) occurring in the hot houses. These are Rhyn-chodemus sylvaticus (Leidy) and Rhynchodemus atrocyaneus Wal-ton, the latter represented by only two specimens and the formerby ten specimens all belonging to the collection of the Departmentof Biology, Kenyon College. It is therefore of interest to recorda specimen belonging to the former species which possesses twoFig 1. Rhynchodemus sylvaticus (Leidy). A Land Planarian from Ohiowith an abnormal pair of eyes. A. Entire individual slightly contracted(x10). B. Head showing relative size of eyes (x25).pairs of eyes instead of the normal single pair. The individualwas among five collected July 4, 1904 under the partially decayedstem of a Virginia Creeper—Ampelopsis quinquefolia, and thepeculiarity was not noted until sometime later when cleared incedar oil preparatory to sectioning.The two pairs of eyes are nearly normal in position, the anteriorpair being 0.26 mm. and the posterior pair 0.33 mm. from the tipof the head in the preserved specimen fixed in hot sublimatealcohol (Apathy) and somewhat contracted. The anterior pair493April, 1915.] A Land Planarian. 499*is nearly twice the diameter of the others. No peculiarities of thisnature have thus far been noted among land planarians althoughvonGraff ('99) in his monograph briefly discusses certain varia-tions in other organs.It is of interest to extend the range of our land planarians andthose engaged in work in Invertebrate Zoology should be able tofind them, particularly on summer mornings after a rain, underpartially decayed boards on lawns, in orchards, etc., in companywith young snails which they superficially resemble.R. sylvaticus was collected by Leidy in 1851-58 and the materialevidently lost. Since then the writer has taken it at Gambierand Urbana, 0., and at Meadville, Pa. It is about 10 mm. long,grayish black with two darker longitudinal lines dorsally. R.atrocyaneus is about 20 mm. long when in a living condition, anduniformally dark blue in color. It has only been found in Gambier,O. When collected, specimens should be killed almost immediatelywith some hot "killing fluid" inasmuch as they die and disintegratevery quickly. They may however, be kept alive for several hoursin a small clean vial provided there is also placed within a pieceof a partially decayed leaf.Gambier, O.

A Land Planarian with an Abnormal Number of Eyes

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A Land Planarian with an Abnormal Number of Eyes

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