360 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



in the middle, and slightly developed tentacular projections at the end. 

 The whole organ has the appearance of being part of the foot rather 

 than an oral veil. 



The branchiae are as described by Abraham. In the specimen which 

 I dissected they consist of 22 simpljr pinnate laminae, set in a cavity 

 1-5 mm. deep. It does not seem probable that this pocket can ever 

 close over the branchiae, but still it is a distinct cavity and not merely 

 a differentiated part of the dorsal surface. 



The intestines are of a uniform yellow colour. On the top of them 

 lies a dendritic organ, probably the kidney. The blood- gland is single. 

 In the central nervous system (which is somewhat decayed) the pedal 

 ganglia seem to be large and round, and the cerebro-pleural ganglia 

 divided into two fairly distinct parts, both of them triangular and 

 elongate. The ej^es are set on short stalks. 



The buccal mass is fairly large. The top part of it is formed by 

 a sessile crop, divided into two halves longitudinally. No striation 

 is visible, but it may have disappeared. The labial armature is 

 distinct, and composed of bent rods with rather wavy outlines and 

 swollen ends. Two blade-like thickenings or projections are developed 

 on the cuticle. Abraham's description of the radula is not correct. 

 The formula is 26 X 3 + 1 . . 1 + 3. The first lateral (Fig. 9^;) is 

 dark-brown and large, much as in Adalaria proximo,, simply hamate, 

 not denticulate ; the base is very large in proportion to the shaft. 

 The three outer teeth (Figs. 9b-d) are roughly oval plates, decreasing 

 in size outwards, and each bearing a ridge. The liver cavity seems 

 to act as the stomach. The intestine describes a very short coil in 

 front and then runs backwards. 



The genitalia are somewhat decayed, but some features are still 

 plain, particularly the extraordinary length of both the male and 

 female ducts. The vas deferens, which is rather thick, seems to wind 

 under the buccal mass. It is armed with minute transparent scales, 

 which under the highest power are seen to bear a small prominence. 

 The spermatotheca is large, the spermatocyst smaller and round. 

 They arise from an elaborately coiled duct, which surrounds them with 

 ample convolutions and apparently passes into the vagina. The 

 hermaphrodite gland seems to be spread over the liver in the usual way. 

 I think it possible that this species is identical with the animal 

 subsequently described by Aurivillius (Vega Expedition, vol. iv, pp. 372 

 and 380) as Doris {Adalaria) Siberica, and by Krause (Mollusken von 

 Ostspitzbergen, in Zool. Jahrb., 1892, p. 364) as Doris [Jcanthodoris) 

 Siberica. The agreement in the buccal parts is remarkable, and 

 Krause says "die Vagina war sehr lang, 40mm. bei dem grossern 

 Stiick." But neither observer notices the gill-cavity, though they 

 mention that the gills are more numerous than is usual in Acanthodoris. 

 Yet the said cavity is perfectly plain in all three specimens of 

 Calycidoris, and looks like a natural and conspicuous feature. The 

 habitat of Calycidoris is unknown, but according to the records of the 

 British Museum it was obtained by J. 0. Goodridge, a surgeon in the 

 Royal Navy, who is known from other entries to have collected in 

 Berino- Straits and on the west coast of South America. 



