50 PROCEEDINGS OF THE ACADEMY OP 



the first six abdominal segments, about 0-31. Length of telson, about 0*14 

 inch ; do. of stylets, near 0-13 inch. Length of lower or outer antennae, not 

 less than 0-38 inch, (probably mo r e), of which the peduncle forms 0-15 inch ; 

 do. of inner, near 0*40 inch. Breadth of thorax, 0-13 inch. 



DECAPODA. 



MACRURA. 



? Genus ANTHRAPALiEMON, Salter, 1861. 



The genus Anthrapahcmon was proposed by Mr. Salter in the Quarterly Jour- 

 nal of tbe Geological Society of London, vol. xvii., p. 529, for the reception 

 of a Crustacean from the Coal Measures of Scotland. His description of the 

 genus reads as follows : 



" Carapace scarcely so broad as long, (except when crushed flat), simple, 

 Hatter than semicylindrical, the sides a little arched outwards. A strong 

 central ridge in front, projecting as a thick (serrate?) spine is separated by a 

 concave space, or slight furrow, from a posterior central ridge, which only 

 occupies (in the type species, Grossarii) a small portion of the length. Front 

 margin serrated. The outer antennas have wide, square basal joints, appar- 

 ently without any advantage ;* the 2d and 3d joints not much oblique ; the rest 

 about as broad as long. Abdomen as broad as long, of six joints (besides 

 the telson), broad and very short ; the pleurae, except the 2d, pointed. Tel- 

 son very broad ; appendages to the penultimate joint, double on each side, 

 subtrigonal, broad." 



The name Anthrapalxmon was proposed from its supposed affinities to the 

 recent genus Palxmon, but Prof. Dana thinks it more nearly related to uftjlea 

 and Galathea. 



Anthkapal.emon gracilis, M. & W. 



It is with considerable doubt that we venture to refer this species to Mr. 

 Salter's genus, the only specimen we have seen being imperfect, and not in a 

 condition to show the more important characters. In form and general 

 appearance, however, as well as in such of its details .as can be made out, it 

 seems to agree well with that genus. The specimen consists of the abdomen 

 and caudal appendages, (in a crushed condition), and an impression in the 

 matrix of the under side of the carapace, the outer pair of antennas, and ap- 

 parently of the eyes. The carapace, as seen from above, presents nearly an 

 oblong form, excepting that the lateral margins are moderately convex in 

 outline; the two extremities are truncated, and the breadth nearly or quite 

 equalling three-fourths the length. Its lateral margins, in front of the mid- 

 dle, are each finely serrated by six small, sharp, projecting points as in the 

 type of the genus, excepting that they are sharper, and directed more oblique- 

 ly forward. At each antero-lateral angle, there is also a considerably larger 

 projecting point, forming a short spine, exactly as in the type of the genus, 

 excepting that it is extended more nearly directly forward. The outer pair 

 of antennae are moderately stout: each peduncle showing three joints, di- 

 minishing rather gradually in size, the first longer than wide, and the other 

 two apparently of nearly equal length and breadth, aud obliquely articulated. 

 The flagellum is narrower at its base than the last joint of the peduncle, and 

 composed of very short segments, which are scarcely more than one third as 

 long as wide. The entire length of the antennas cannot be determined, as 

 neither flagellum is entire in the specimen examined, but as the portion re- 

 maining tapers very gradually, they were probably rather long. They are 

 both, in the specinu-D examined, deflected abruptly outwards, nearly at right 

 angles to the longer diameter of the carapace, which would seem from the 



He not this a misprint of the word appendage t 



[Mar. 



