6^. 7. Smith — Crustaceans of the Atlantic Coast. 95 



the armament of the coronal extremities, with the mandibles of J'ar- 

 erythrops obesa. In each mandible the inferior angle of the crown is 

 separated by a broad space from the superior, or molar, angle. The 

 inferior edges and the molar processes in both mandibles are almost 

 exactly as in Parerythrops obesa : the inferior edge itself is much 

 alike in the two mandibles, being composed of about four irregular, 

 obtuse teeth, l)ut the dentiform process just within the edge differs in 

 the two mandibles; in the right it is more slender and prominent 

 than in the left, and enlarges at the extremity, which is armed with 

 several rather slender teeth ; while in the left the process is shorter 

 stouter, and terminates in shorter teeth. The space between the 

 armament of the inferior edge and the molar process is, in each man- 

 dible, furnished with twelve to fourteen setifoi*m teeth which are 

 very different in the two mandibles: in the left they are slender 

 crowded closely together, and armed with minute, spiniform teeth'- 

 while in the right they occupy a much larger space, are thin, acutely 

 triangular, and wholly destitute of secondary spines or dentations 

 except, possibly, one or two exceedingly minute spinules at the bases 

 of a few of them. The mandibular palpi have almost precisely the 

 same form, proportions, and armament of spines and sette as in Par- 

 erythrops obesa. 



The first maxillae are throughout exactly as in Parerythroiys obesa. 

 The second, also, have very nearly the same form and proportions as 

 in that species ; the outer lobe, or scaphognath, however, differs in 

 being broadly oval, margined with twenty-five to thirty setce and in 

 having the anterior extremity rounded and tipped with four seta3 

 two of which are very distinctly on the inner margin inside the tip 

 while in Parerythrops obesa the scaphognath is triangular anteriorlv 

 is margined with only fifteen to eighteen setae, none of which are 

 really on the inner margin, although there are two at the narrow tip- 

 the three lobes of the protognath and the two segments of the palpus 

 (endognath) are exactly as in Parerythrops obesa., except that they 

 are furnished with a few more setae. 



The endognath in the maxillipeds is almost exactly like this part of 

 the same appendage in Parerythrops obesa. The exognath differs 

 in being very slightly larger proportionally and in having thirteen or 

 fourteen segments in the flagelliform portion. The endognath in the 

 first gnathopods (second maxillipeds) does not differ from the same 

 part in Parerythrops obesa, except that it is armed with a somewhat 

 greater numbei- of setae and spines, particularly on the distal part of 

 the outer margin of the longest segment (merus). The exognath is 



