July 28, 1911] 



SCIENCW 



127 



all around, and the very broad central area 

 occupied by irregular, more or less elon- 

 gated reticulations. Thus the scale comes to 

 closely resemble those of the MormyridEE. As 

 it now seems evident that the ancestors of the 

 Teleosteans must have had reticulated scales, 

 or at least that the ordinary radial sculpture 

 is derived from the reticulated type, this 

 Moxostoma scale must be regarded as uniquely 

 primitive or atavistic for the general group 

 to which it belongs. 



3. Dr. G. A. Boulenger has very kindly sent 

 me scales of the eseciliid amphibian leh- 

 thyophis glutinosus. These are very small, 

 embedded in the skin, cycloid in form. The 

 pattern is extremely characteristic, consist- 

 ing of concentric grooves connected at inter- 

 vals by cross-lines, the whole effect being like 

 that of bricks in a wall. The concentric 

 grooves are probably not circuli, nor can I 

 make out anything corresponding to the cir- 

 culi of fishes. In parts of the scales, however, 

 the markings become irregular, producing a 

 reticulation which closely simulates that of 

 the reticulate-scaled fishes. I believe that the 

 scales are really comparable to fish-scales, 

 and that the sculpture is the same as the 

 radial sculpture of fishes. No fish scale has 

 been seen resembling in detail that of Ichthy- 

 ophis; such scales as those of Chrosomus are 

 superficially similar, but owe their circular 

 lines to different elements.^ 



t. d. a. cockerell 



University of Colorado 



notes on the genus ttpha and its nematode 



root gall heterodera radicicola 



(greeff) mull. 



During the summer of 1908, while investi- 

 gating some problems connected with the root 

 system of Typha latifolia, I found a number 

 of abnormal growths on the rootlets. These 

 growths appeared as irregularly spherical or 

 fusiform enlargements, varying in size from 

 1 to 5 mm. in diameter. They were identified 

 by Professor Atkinson as root galls caused 



" Since this was written, I have found that a 

 deep-sea eel, SynaphoirancJius pinnatus, has scales 

 curiously similar to those of Ichthyophis. 



by the nematode Heterodera radicicola. I 

 have collected these galls at the same station 

 (limnology station of Cornell University) 

 three successive years, but have never found 

 them on Typha in any other locality. 



Professor Atkinson' thought, from his ob- 

 servations of this worm on potatoes and 

 tomatoes, that, if favorable opportunity 

 should occur for its introduction in the north, 

 it might become a pest. Webber and Orton" 

 say it will never become a serious pest in the 

 north, as'_severe cold kills the worm. Van 

 Hook reports the worm as wintering in gin- 

 seng beds which had been mulched and also 

 in protected forest beds. This worm has been 

 a serious pest to ginseng in the north. 



Stone and Smith* found the galls on out- 

 door plants, but concluded that they were 

 transient. 



The plants observed by me in the Cayuga 

 marshes are located along the shore line of 

 one of the arms of Fall Creek where moisture 

 is plentiful in the soil all winter. Winter 

 observations prove that the soil in which the 

 galls are found does not freeze. None of the 

 galls have been found more than eighteen 

 inches below the surface. 



L. N. Hawkins 



CORRELATION NOTES 



In describing the fauna of the lloorefield 

 shales of Arkansas' Mr. George H. Girty lists 

 and describes the following fossils among 

 others from the region: Producius inflatus 

 var. coloradoensis Girty (?),' Productus ar- 

 Tcansanus var. muUiliratus Girty,° and Dia- 

 phragmus elegans Norwood and Pratten.* By 

 a comparison of the figures of these fossils on 

 plate iv.° with fossils which the writer collected 



* Bull. 9, Alabama Exp. Sta. 



'V. S. Dept. Agr., Bur. Plant Ind., Bull. 17, 

 1902. 



'Cornell Agr. Exp. Sta., Bull. 219, 1904. 



'Bull. 55, Mass. Agr. Exp. Sta., 1898. 



^ ' ' The Fauna of the Moorefield Shale of Ar- 

 kansas, " U. S. Geol. Survey, Bulletin No. 439. 



^Ihid., pp. 42-43. 



' Ihid., p. 43. 



*J6i<J., pp. 51-52. 



'Ibid., plate iv. 



