ANTHOSOMA CEASSUM. 109 



entirely by two large foliaceous elytraform circular 

 plates, the inner margins of which partly overlap each 

 other on the dorsal aspect, these plates being orna- 

 mented with numerous minute scattered punctures or 

 depressions. 



Antennules moderately short, and composed of 

 six sparingly-setiferous joints; the antennas stout, 

 three-jointed, longer than the antennules, and armed 

 with strong terminal hook-like claws. First maxilli- 

 peds slender and feebly armed, apparently consisting 

 of three joints, the end one being small and of a 

 peculiar shape ; second maxillipeds short, very stout, 

 and furnished with strong terminal claws. Thoracic 

 legs in the form of thin and broadly-foliaceous plates 

 each with a distinct notch on the inner margin, con- 

 cealing the genital segment as well as part of the 

 abdomen. Caudal rami narrow and moderately elon- 

 gated. Length about 15 mm. Egg-strings long and 

 slender, reaching in length from 40 to about 50 mm. 



The shield is of a chitinous texture, the colour on 

 the sides is yellowish but merging into blackish-brown 

 along the middle and towards the front ; the elytra- 

 form plates and thoracic feet, which also appear to be 

 slightly chitinous, are whitish with a slight tinge of 

 yellow. 



Male. The male has a close resemblance to the 

 female, except that the large dorsal plates which cover 

 the posterior portion of the female are wanting. 



This interesting species was found on what was supposed 

 to be a porbeagle shark (Lamna cornubica) captured off the 

 coast of Scotland in October 1904, by one of the trawling 

 steamers which make only short runs from Aberdeen and 

 which are locally known as " short trippers." Two specimens 

 of the Anthosoma were obtained the one described here and 

 a smaller one, probably a male. We are indebted to the 

 kindness of Mr. Irvine, Aberdeen, for the specimen here de- 

 scribed. Dr. Baird states (op. cit., p. 299) that a specimen 

 was " discovered sticking to a shark (the Lamna cornubica) 

 thrown ashore at Exmouth, Devonshire, by T. Smith, Esq., 

 of the Temple, who sent it to Dr. Leach, British Museum." 



