52 MARINE INVEKTEBRATA OF GRAND MANAN. 



bears a sliglitly curved finger, or terminal unguiform joint, which overlaps the thumb 

 for nearly half its length. In the second pair of legs, the antepenult joint projects 

 into a curved thumb of about half the length of the penult article, which forms a 

 thick ovate hand of great size, equalling in length more than that of the first three 

 thoracic segments together. Its finger is strong, and curved. The remaining legs 

 are rather long, but very slender, with short terminal joints. Caudal stylets long, 

 slender, nearly smooth, and pointed. Color, in life, pale yellowish. Length, 0.44 

 inch; height at the fourth segment, 0.14 inch; breadth, 0.12 inch. Dredged in 

 thirty fathoms, on a shelly bottom off Low Duck Island. 



AcANTHONOTUS SERRATUS, St. Oiiiscus serratus, 0. Fabr., Fauna Grtinl., No. 

 237. Amphithoe serra, Kroyer, Gronlands Amfipoder, t. 2, f. 8. This species is very 

 beautiful in coloration, jrhich consists of deep pink annulations, one to each seg- 

 ment of the body, on a yellowish-white ground. The anterior half of each ring is 

 thus pink, and the posterior half white. The last pair of epimerals is also con- 

 spicuously colored. The anterior halves of the antennse are also red. This species 

 occurred in thirty-five fathoms on a gravelly bottom, north-east of Nantucket Island. 



Amphithonotus^ catapiiractus, St., n. s. Body robust, carapax very stout, with 

 seven carinas extending for greater or less distances on the back and sides, viz. : 

 one strong median dorsal carina commencing on the first thoracic segment, becom- 

 ing strongly dentate on the last thoracic segments, and ceasing on the second 

 abdominal ; the next two carina (proceeding outwards) are developed in the form 

 of strong teeth on the last two thoracic, and all the abdominal segments, being 

 spine-like on the second, and almost lamelliform on the last four abdominals ; the 

 next carinse are sharp ridges, extending along the bases of the epimera, and slightly 

 continued on the first two abdominal segments ; and the last, or outer carinae, are 

 very short, extending only along the bases of the last three pairs of legs. Epimera 

 large, angular. Head with very large, rounded, convex eyes, and a rostrum of 

 great size, which is elongate-triangular, pointed, curving downwards, concave above, 

 and with a sharp median ridge below. Antennae slender, about equal in length, 

 and one-fourth the length of the body. Legs of the first two pairs with large ovate 

 hands, dentate below, with curved fingers of about two-thirds their length ; ante- 

 penult joints with slight thumbs. The remaining legs are slender ; femora of pos- 

 terior pairs but slightly expanded. Caudal stylets all biramous ; external rami of 

 the last two pairs shorter than the inner ones. Tail terminating in a subquadrate 

 lamella. Color very variable, generally dark reddish or brown, variegated and 

 mottled with white. Some specimens were of a uniform deep purple, others pure 

 white. Eyes yellowish or vermilion colored, with a black dot in the middle. 

 Length, half an inch. This is one of the most curious, and by far the finest species 



* AmphitJwnofas, Costa, in Catalogo Crustacci Italiani, per Fr. Gugl. IIopo, Napoli, 1851. " Illis ex 

 Aniphithois sp. constitutum est hoc genus, quas dorsum vel omuino carinatum et spinosum, vel saltern 

 quibusdam abdominis articulis si non et thoracis postice in spinam vel dentem productis habent ; ex quo 

 peculiarem habitum pr»bent, Amph. marionis, Edw., A. panop/a, Kroyer, A. carmahis, ejusd. et quae 

 sequntur ad hunc genus pertinent." This genus is synonymous with Acanthosoma, Owen ; which name, 

 however, is preoccupied in insects. It may include those .species of Amphitlwc which have dorsal carina;, 

 and small epimera of the fifth pair. 



