522 The American Naturalist. [June, 



Lateral-Line Organs of Sharks. — Ewart and Mitchell, in two 

 papers 1 describe the sensory canals in Lsemargus and Raia. The 

 lateral-line organs consist of two systems of canals and of minute 

 sensory follicles. The so-called sensory canals open to the surface of 

 the skin by numerous tubules, while the ampullar canals are enlarged 

 at the proximal ends, and give off neither tubules nor branches. 

 Previous authors have described the sensory canals according to posi- 

 tion ; Ewart and Mitchell think innervation should be the basis of 

 grouping. The canals receive their nerve supply, 1, from the facialis 

 or, 2, from the vagus, the latter innervating the lateral canal. Of the 

 canals innervated by the facialis three main stems are recognized, the 

 supraorbital, supplied by the ophthalmic ; the infraorbital by the 

 buccalis ; and the hyomandibular by the corresponding divisions of 

 the facialis. The further details have little interest in an abstract, 

 except the great extension of the hyo-mandibularis canal over both 

 surfaces of the pectoral fin of the skates. In this connection the editor 

 may state that some as yet unpublished researches tend to show that 

 these canals promise to throw considerable light upon the phylogeny 

 of the fish-like vertebrates. 



Parallel Color-Patterns in Lizards.— In The Naturalist 

 for December, 1891, p. 1135, I called attention to the identical color- 

 patterns displayed by the varieties of our two South-western species of 

 Cnemidophorus, C. tessellatus and C. gularis, and the general simi- 

 larity these species present to the Lacerta muralisof the Mediterranean 

 countries, in color variations, which are pointed out by Prof. Eimer. 

 Having recently published a paper on Cnemidophorus in the Trans- 

 actions of the American Philosophical Society, I give two plates illus- 

 trating these facts. Plate xviii represents the two species of Cnemido- 

 phorus, A to F the C. tessellatus, and G to L the C. gularis. A is 

 the color-pattern of the young and half-grown ; B is C. t. perplexus B. 

 and G., adult; C, G. t. tessellatus a ; D C.t. tessellatus ; E C.t. tessellatus 

 y; F C. t. rubidus Cope; G C. gularis young and half grown ; 

 H do. adult ; I and K, C. g. sealous Cope a and |3;LC.y. semifasciatus 

 Cope. Plate xix represents some of the variations of the Lacerta 

 muralis. A represents the young coloration ; B the var. L. in. carnpestris; 

 C the L. m. albiventris ; D L. m. maculata ; E L. m. tigris.—E. D. 



1 Zooi. Anz., xv. 116, 118, 1892- 



