Dr. Phillppi on a new Species of wood-horing Crustacea. 95 



scription. The animal, including the antennae and caudal ap- 

 pendages, is 4 J"' long, and without them 2 j'", and about |" 

 broad. The head is narrowest, and as long as the two follow- 

 ing segments, the body becomes gradually broader from the 

 head, without however departing considerably from the linear 

 form. The eyes are small and round, the superior antennae of 

 moderate length, setaceous, and with seven articulations. The 

 inferior antennae are one and a half times as long and consist 

 of six articulations, the two first are very short, the remainder 

 gradually increase in length, become flatter, and the last are 

 densely beset with cilia, so that they appear rather to be an 

 organ for swimming than for feeling. The pectoral segments 

 are of equal length and have their lateral parts only slightly 

 developed. The tail or abdomen consists of five segments : 

 the two first resemble the pectoral segments ; the third seg- 

 ment bears on the centre of the back a long curved horn 

 which exactly resembles that of the Sphinx caterpillar, and on 

 each side two small tubercles. The fourth segment is one and 

 a half times as long as broad, beneath somewhat flat, above 

 concave, covered with small protuberances and ciliated on the 

 lateral margins. They are especially distinguished by two small 

 hooks in the centre of the hinder margin. This segment bears 

 on each side two pairs of curious appendages w^hich are arti* 

 culated on to its base. The front appendages are perpendicu- 

 larly directed and consist of three longish rounded flaps which 

 are all thickly beset with long hair, and of which the front 

 one is the largest, the hinder one the smallest. The lateral 

 pair of appendages perfectly corresponds to one of the caudal 

 appendages of the Gammari, and consists of a stalk which 

 supports two small acute laminae. The fifth segment is very 

 short, exhibits superiorly in a fissure the anus, above in the 

 centre, and inserted at its base (or to the hinder margin of the 

 fourth segment) an oval lamina, and at its extremity an enor- 

 mous joair ofpincerSy which are nearly twice as long as the two 

 last caudal segments. Their two laminae are compressed, 

 somewhat diverging, attenuated towards the apex, and bent 

 in the form of a hook, and they have serrated margins. The 

 fourteen feet increase posteriorly in length, but not consider- 

 ably. The two front ones have at their extremity a curved 



