NUDIBRANCHIATE GASTEROTODA. 



37 



The anterior genital mass was of about the same form as in the typical species, 6 mm long 

 by a breadth of 4 mm and a thickness of 5""". The ampulla of the duct of the hermaphrodite gland was 

 also as in the typical species, forming several windings. As in the following species') a little whitish 

 prostate gland of a diameter of 2""" was found, formed of fine interwoven windings; the muscular 

 seminal duct arising from this gland, was loosely rolled to a little bundle, also as in the following 

 species, its thinner fore end plunged into the top of the little preputial bag which projected exter- 

 nally with its foremost edge; from this bag the highly tapering glans penis projected 3 Rlra2 ). The 

 seminal vesicle as in the other species continuing in its powerful duct, the opening of which was seen 

 in the depth of the vulvas) that projected externally. The white and whitish albuminous-mucous 

 gland formed the greater part of the anterior genital mass. 



By the examination and the specific determination of Nudibranchiata it is frequently an awk- 

 ward thing that this examination and determination has to be made by the means of only one indi- 

 vidual, especially when the forms of this individual as far as possible have to be spared. Many of 

 these animals seem to be able to vary considerably as well with regard to the outer as to the inner 

 structure. The individual here examined, agreed in the outer form more with the typical species, in 

 the nature of the mandibles and the presence of a prostate gland with the following species, but 

 differed from both bv the structure of the radula. 



3. Gon. atypica, Bgh. n. sp. 



PL IV, figs. 6—15; PI. V, fig. 1. 



Of this form one specimen was taken on July n ,h 9-30 a. m. on 66° 43' Lat. N., 55 = 57' Long. W. 

 with the trawl from a depth of 88 faths (temp. 2°6— 2°). 



The individual, which was well preserved in alcohol, was generally of a whitish colour-*). — 

 It surpassed in size the hitherto found Gonieolides; its length?) was 5\5 cm , by a breadth of the back 

 of r6 cm and a height of i'3 cm . The length of the tentacles in this colossal individual rose to n n,m , and 

 that of the rhinophores to i5 nim ; the breadth of the lateral parts of the back, that were set with 

 papillae, appeared to rise to 4 — 5"™ and the remaining papillae rose only to a length of at most 3"™. 

 The length of the foot was almost 5-''" by a breadth of up to r6 cm ; the breadth of the foot-brim was 

 3 mm , and the length of the tail 3 mm . 



The form is somewhat flattened, and the height evenly decreasing backward, very slight at 

 the hinder end. The head (figs. 6, 7), the region between the rhinophores and the tentacles, sloping 



i) It is hardly possible that I should have failed to notice the existence of a prostate gland in the typical species. 



2 ) Comp. R. Bergh, die Nudibranchien . . . des Willem Barents . 1. c. p. 18. Taf. Ill, Fig. 25 ef, 2. 



3) Comp. 1. c. p. iS. Taf. Ill, Fig. 2 f. 



1. According to Sars the colour of the typical species is commonly yellowish white, only the lateral parts of the 

 back (on account of the liver) being yellowish brown; in the median line of the body, especially on the sole of the foot, a 

 minium-red stripe shone through. 



5) The (3) individuals of Gon. typica examined by Sars, measured I2 mm , the (3) specimens earlier examined by me, 

 measured 2—2,3"" *" length. 



