GA.MMAUIll.K. 121 



to this {^enus, only ditfVring from it, ai)i)arontly, in the telson uoii- 

 sistinj;; of two long spines :— 



*' Body smooth and shining, slightly compressed, but rounded above, 

 broadest anteriorly. Cephalon roiindod, with a prominent down- 

 ciuA-ing rostrum. Pleon, constituting nearly one-half of the body, 

 much compressed. Coxoc not very large. Eyes red, and rather 

 large. 8u])erior antennae two-thirds as long as the inferior, thick 

 at theii" bases, b\it tapering suddenly after their junction with the 

 long accessory flagcllum, wliicli is nearly one-half the length of 

 the principal one. Inferior antcnnuo with very thick basal joints, 

 and equalling in length two-tliirds that of the body, theii- liagella 

 0(mstituting more than one-half their length. Pereiopoda hairy, 

 tJl terminating in short hooked dactyla. Gnathopoda slender, 

 longer than the pereiopoda, with the carpus* in each a little ex- 

 panded, but scarcely sufficient to form a hand. Posterior pair of 

 pereiopoda much shorter than usual t, and provided along the 

 edges with short spine-like hairs. Fii'st three segments of the 

 pleon serrated above on their posterior edges ; last three com- 

 pressed above into sharp spine-hke projections, of which the middle 

 one is the longest. First pair of pleopoda very long and slender, 

 projecting beyond the others. Telson consisting of two long spines. 

 Colour wine-yellow ; inferior antenna) annulated with reddish. 



" Length 0-32 inch. 



" Hah. Dredged in 40 fathoms, on a soft muddy bottom, off Long 

 Island, Grand Manan." — Sthnjpson. 



32. PROSOPONISCUS.— (i^oss/Z.) 



Trilobites, Schhthcim, r,tn'fiut. I&IO, p. 41. 



rtiliuocrangon, ''^chairrot/i, Ziitschr. Dent. Gcol. Gcsell. 1854, vi. p. 5(30. 



Cei:>ludon cm^ed down anteriorly. Pei'eion having the segments 

 short, subcqual. Pleon having the segments long and deep ; the 

 fii-st deeper than the second. Coxa) small. The other parts im- 

 perfect. 



1. Prosoponiscus problematicus. (Plate XXI. iig. 3.) 



Prosoponiscus problematicus, Kirkby, QuaH. Journ. Geol. Soc. xiii. 



p. 213. 



Spence liafe, Quart. Journ. Geol. Soc. p. 187. pi. (i. f. 1-7, 1858. 

 Trilobites problenuiticiLs, Svhlotltcitn, PetrefuH. 1820, p. 41. 

 Palicocrangon problcniatica, Scftauroth, Zcitschr. Dcut. Geol. Gcsell. 



1854, vi. p. 5tJ0. pi. 22. f. -la-e. 



Cephalon, pereion, and pleon slightly carinatcd. Posterior margin 



* "AntepenuUimate article," aucf. I. r. 



t This character approximatea it to PhoxttH. 



