ELIOT : NUDIBRANCHS AND TECTIRRANCHS FRO^r INDO-PACIFIC. 305 



surface arises a diverticulum, 4.5 mm. long, and studded with knobs. 

 The salivary glands consist of a bunch of filaments at the end of a 

 short, stout but tapering duct. 



Just inside the mantle cavity is a large pear-shaped papilla on 

 which the female orifice is situated. The penis, which lies behind 

 and below the right rhinophore, is exserted in the largest specimen 

 and is white, 1.5 mm. long and very thin, but thicker at the base. 



I think this species may on the whole be referred to L. viridis 

 Pease, though differences in the details of coloration are not wanting. 

 I have compared the Pacific specimens with others brought by Mr. 

 Crossland from Boa Vista, Cape Verde Islands, which seem referable 

 to Z. sieboldi {olivacea). 



Lophocercus sieboldi Krohn. 



Two specimens from Boa Vista, Cape Verde Islands, are probably 

 referable to this species. The tails have been broken ofT (possibly by 

 autotomy) but are preserved. The body is about 12 mm. long and 

 9 mm. broad. The tail about 19 mm. long. 



In most points, such as the branchia, buccal mass, salivary glands, 

 diverticulum on the oesophagus, etc., these specimens closely resemble 

 those from the Indo-Pacific. The radula is not appreciably different. 

 It contains 11 teeth in the ascending series, 25 in the descending, 

 and 12 in the heap. Perhaps the following points constitute real 

 differences. 



There is no trace of blue spots or ocelli. The colour appears to 

 have been olive with yellowish markings. In one specimen a rich, 

 bright olive green predominates, in the other yellowish brown with a 

 little yellowish green here and there. The shell is milky white, 

 semitransparent, and covered with a perfectly colourless transparent 

 periostracum. It is smooth, not striated, but bears a few marks like 

 scratches. It is somewhat broader in proportion than the shell of 

 the Pacific form, the measurements being about 1 1 mm, long by 9 mm, 

 broad, as against 10 mm. by 6 mm. for L. viridis. In both specimens 

 there are traces of a furrow on the anterior margin of the foot. The 

 visceral mass is flatter than in L. viridis, and adheres to the foot over 

 a wider area. The wings do not seem to form so distinct a chamber 

 and are flattened out at the sides as if they were used as a creeping 

 surface. But possibly this configuration is chiefly due to a difference 

 of attitude. There are only a few minute yellow papillae on the 

 wings and caudal crest. On the roof ot the mantle cavity is a tri- 

 angular area which may represent the postbranchial gland, but it is 

 colourless and not chalky white as in the Pacific specimens. But 

 this white colour may be merely due to a secretion and not indicate 

 a difference of structure. There is perhaps a real difference in the 



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