Das System der Polycladen. 463 



34. Diplonchus marmoratus Stimpson. 

 Stimpson 1S57. 78. pay. 4, 11. — Diesing 1862. 89. pag. 545. 



»Oblongo-ellipticus, antico subiingustatus, postice rotundatus, supra brunneus, maculis albis renifor- 

 iiiibus marmoratus. Ocelli in pajiilla elliptica bilobata; alii in acervum linearem ab hac papilla antrorsum 

 extensum. Long. 3,3: lat. 1,4 poll. 



Hab. Ad oras insulae »Ousima«; sublittoralis inter lapillos.« 



Anhang zur Familie der Planoceriden. 



Mangelhaft heschriebene Planoceriden, deren generische Stellung liauptsächHch wegen 

 des Fehlen.s anatomischer Angaben nicht festgestellt werden kann. 



35. Planocera elliptica Girard. 



GiRARD 1847. 54. pag. 300—308. Ontog. — ') Girard 1851. 59. pag. 251—252. — 

 Girard 1851. 60. Ontog. — '^) Girard 1851. 64. pag. 3. — •") Girard 1854. 72. 27 pag. Ontog. 

 ■ — Stimpson 1857. 78. pag. 5. — Diesing 1862. 89. pag. 561. 



1) »This species I have mentioued before the Am. Ass. f. tbe Advanc. of Science, when describing 

 its embryology. It is quite common on the sea-coast of Massachusetts. Its greatest size is about three 

 quarters of an inch, its form elliptical, its margin entire, its color grayish yellow. The genus Planocera 

 of BL.\ra\'XLLE is takeu here as including Stylochus of Ehrenberg.« 



2i »Form elliptisch, regelmässig, mit einfachem, ungetheiltem Rande. Vordertheil schmäler als der 

 Hintertheil. Mund in der Mitte der unteren Fläche, an Länge mehr als Y3 der ganzen Länge betragend. 

 Farbe gränlich oder röthlich gelb. Grösste Länge 74"- Sehr gemein. Boston, Beverly, Chelsea. Befruch- 

 tung Mai und Juni.« 



3 ))Excerpte der Girard' sehen Darstellung der Ontogenie von Planocera elliptica s. S. 318, 320, 

 321, 350 — 351, 371—372. 



36. Planocera nebulosa Girard. 



') Girard 1853. 69. pag. 176. — Diesing 1862. 89. pag. 561. — ') Verrill 1873. 112. 

 pag. 632, 325 und 332. Tab. XIX. Fig. 100. 



1) »Body about half an inch in length, and a quarter of an inch wide, elliptical, provided with two 

 (vhitish, protractile and retractile tentacles, a tenth of an inch in height when protruded. Ground colour 

 dark hyaline, ^-itli dark crowded mottlings, giving to the whole a dark grayish appearance. From the ten- 

 tacles a medial dark brownish red line extends to the posterior margin. Beneath gray, except two whitish 

 convolutions, the genital apparatus seen by transparency , anteriorly tinged with pink. The perii^hery is 

 whitish hyaline. Dredged just below low water mark o'n a soft muddy sand, east of Fort Johuston.« 



2i »Savin Rock near New Haven, under stones at low-water, Charleston, S. C. (Girard;. 



»Occasionally found on the under side of stones. One of these, the Planocera nebulosa is usually 

 about haK an inch wide and three fourths long, but may become nearly circular, or may extend into a long 

 elliptical form. It is flat and thin, ■4\-ith flexuous edges. Its color is olive-green above, with a lighter me- 

 dian stripe beilind, and yellowish green below. The tentacles on the back are whitish and retractile.« 



Figurirt auf pag. 332 auf der »List of species iuhabiting the rocky sliores of the souuds and bays.« 



