490 A. M Verrill — Marine Planar lans of Nem England. 



54 fathoms. Off Watch Hill, R. I., 4 to 6 fath. among algfe, specimen 

 with ova, April, 1872 (A. E. V.); off Point Judith, R. I., sta. 784, in 

 20 fath., with ova, 1880; off Block Island, sta. 812, 28^ fath. ; off 

 Gay Head, Martha's Vineyard, 18 fath., 1887; off Cape Cod, sta. 301, 

 27 fath., 1879; off Cape Ann, Mass., at stations 134 and 136, in 26 

 fath., and at sta. 182, in 45 fath., 1878; Eastport, Maine, 1870. 



There is considerable variation, both in external appearance and 

 in the form of the reproductive organs in this species, but I believe 

 the differences observed are due to age, season of the year, presence 

 or absence of ova, and the amount of contraction when preserved. 

 As it might be doubted w^hether all the forms can be referred to T. 

 folium, I have thought it well to give here a special description of 

 the original type-specimen of that species, for comparison with the 

 later and better specimens, described above. 



IJescription of the original specinien from life: — Body very flat, 

 foliaceous, with the margin thin and undulated ; outline very change- 

 able, broad-ovate, narrowing to an obtuse point at the anterior end ; 

 sometimes oblong or elliptical and but little narrowed anteriorly. 



Ocelli in four groups, near the anterior end ; the anterior or cere- 

 bral clusters are parallel, narrow, elongated, Avidest in the middle, 

 close together, almost blending on the median line, and composed of 

 many very minute ocelli, less easily seen than those of the other 

 clusters ; the terminal ocelli are largest ; the dorsal or posterior 

 groups are rather small and irregular ; in some states of extension 

 often triangular, with the pointed end backward ; marginal ocelli 

 numerous, but minute, in two or three rows near the edge, with 

 others scattered over the frontal region, visible only when much 

 magnified. 



Color, pale yellowish flesh-color, veined with dendritic streaks of 

 darker flesh-color and whitish lines ; an interrupted longitudinal 

 whitish streak in the middle, over the stomach and pharynx, and a 

 small median whitish streak farther back. 



Length, 20°"" to 25^"™; breadth, lO'""" to 15'""\ 



Off Watch Hill, 4 to 6 fathoms, among rocks and algje, April, 1872- 



Description of the original type as preserved : — This original type- 

 specimen, mounted in balsam, shows man}?- of the anatomical charac- 

 ters (PI. XLiv, figs. 4-4c), but the posterior end had been mutilated 

 in life and only partly healed ; in consequence of this the female 

 repi'oductive organs are not perfect. This also accounts for the 

 broad eraargination of the posterior end, mentioned in the original 

 description. 



