2 6 XriUBRAXCHIATE GASTEROPODA. 



tlie right side of the stomach; it was of an oval roundish shape, 8 mm long by a breadth of 6 mm and 

 a height of 5'50 mm , whitish and yellowish white. In a hollow on the hinder end of the mucous gland 

 the intertwined, opaquely yellowish gray ampulla of the duct of the hermaphrodite gland was lying, 

 measuring, when stretched out, i2 mm in length by a diameter of up to 2 mra ; on the fore end were seen 

 the windings of the spermatic duct forming a little coil; the glans that projected from the penis-bag, 

 was almost cylindrical, 4 mm long by a diameter of i75 mm . Behind the spermatic duct and partly covered 

 by it was the spermatocyst, bent double in the middle, 4 ram long when stretched out, its duct being 

 of about the same length. The mucous-albumiuiparous gland was whitish and yellowish white. 



Fam. Dendronotidae. 



R. Bergh, System d. nudibranchiaten Gasteropoden. 1892. p. 1048 — 1051. 



The Dendronotidae form a group, rather well marked off by its peculiar forms; in this respect, 

 however, but still more by the inner structure, and especially by the structure of the pharyngeal bulb, 

 it proves to be related to the Aeolidiadae. 



The animals belonging to this group, have hitherto only been found in the northern temperate, 

 and especially in the cold seas. 



The rather strongly limited family includes o^Jy two genera, the real Dendrouotus and 

 Campaspe, which latter seemed to be distinguished from the former by a simpler structure of the 

 frontal appendages, of the rhinophoria, and of the dorsal papillae. It is, however, still to be doubted, 

 whether the two generic groups will not prove to be passing into each other, and the examination of 

 the following form seems already to imply such a result. 



Dendronotus, Aid. et Hanc. 



R. Bergh, die Nudibranchien gesammelt wahreud der Fahrteu des Willem Barents in das nordliche 

 Eismeer. 1885. p. 19 — 33 (Bijdragen tot de Dierkunde. Aflevering XIII. Amsterdam. Onder- 

 zoekingstochten van de Willem Barents Expeditie. Gedeelte IV (1886) 1888). 



A little series of species has been referred to this genus, but they are likely to be, for the 

 greater part, reduced to varieties of the typical species. The form examined below, seems, however, 

 to be distinctly specifically different from the typical one. 



1. D. robustus, Verrill. 

 D.robustus, Verrill. Americ. Journ. I. 1870. p. 405. Fig. 1. 



, V. Catal. of marine moll, added to fauna of New Engl. Trans. Conn. Ac. V, 2. 1882. p. 550. 

 D. velifer; G. O. Sars. Bidr. til Kundsk. 0111 Xorges arktiske Fauna. I. Moll. reg. arct. Norv. 1878. 



p. 315 — 316. Tab. 28, Fig. 2; Tab. XV, Fig. 15. 

 I). robustus. V R. Bergh , die Opisthobranchien. Rep. on the dredging oper. off the West Coast of 

 Central-Amer. ... by ... Albatross . (Bull, of the Mus. of compar. zool. at Harvard college. 

 XXV, 10). 1894. p. 141 — 144. Taf. II, Fig. 6— 9; Taf. Ill, Fig. 1. 



PI. Ill, figs. 27—29; PL IV, figs. 1—5. 



