72 PROCEEDINGS OF THE ACADEMY OF [1880. 



teeth strong, finely denticulated (with six to eight denticles) on the 

 inner side of the hook, and with a strong, rounded prominence at 

 the base of this (fig. 18a, 19, 20) ; the external pseudo-plates with 

 the usual curved points (fig. 186). Irregularities in the form of the 

 last were often observed (fig. 23).^ 



The crop entirely as in the typical species, the largest diameter 

 1.3 mm. / 



In the stomach indeterminable animal matter and a little, undeter- 

 minable worm, of the length of 2.0 mm. 



The hermaphroditic gland as usual ; the lobules filled with sperma. 

 The anterior genital mass rather large, measuring in length 4.5 mm., 

 in height 2.5 mm., and in breadth 2.3 mm. ; the left side flat or a little 

 excavated, the right rather convex. The mucous gland, as well as 

 the albuminous gland, white and yellowish-white. The spermatoduct 

 not very long, but rather strong, continued in the very strong penis, 

 that (retracted ) forms the fore-end of the whole mass. The penis has 

 a length of about 3.5 mm., by a diameter of 1.3 mm. ; the inferior 

 end rather constricted ; the superior three-quarters of the organ com- 

 pact, perforated through the axis by the dense coils of the spermato- 

 duct proper ; the inferior one-third hollow, including the curved and 

 pointed glans. 



2. L. muricata (MilUer). Plate IX. fig. 18; Plate XI, fig. lO-Ii. 



Doris muricata, O. F. Muller. Zool. Dan. Fas. Ill, 1789, p. 7, Tab. 



LXXXV, f. 2, 3, 4. 

 Doris muricata, Muller. Sars, (forma /5) Loveu, Ind. Moll. Scand.1846, 



p. 5. 

 Dori<i muricata, Meyer und Moebius. Fauna der Kieler Buclit, I, 1865, 



p. 73-75, Taf. Vc, fig. 1-8. 

 f Lamellidoris muricata, Muller. G. 0. Sars, Moll. reg. arct. Norv., 



1878, p. 307, Tab. Xlll, fig. 6. 



Color flavidus vel luteo-albus. 



Dentes laterales magni hamo denticu'ato sed non usque ad apicem. 



Hah. Oc. Atlanticum septentr. 



The original specimen on which Miiller founded his Doris muricata 

 does not exist, and by his incomplete description it is now completely 

 impossible with full certainty to determine what species was meant by 

 his description. In future the species described by Meyer and Moebius 



' From the presence of only one Individual, the examination of the radula 

 was extremely difficult and limited, as also that of the genital organs. 



