THALASSINIDEA. 



GENUS TRYPJ3A, Dana. 



Callianassae maxillipedibus externis pedibusque affinis. Antennae in- 

 ternee subpediformes, flagellis articulo basis ultimo br&vioribus. 



Near Callianassa in outer maxillipeds and feet. Inner antennae sub- 

 pediform, flagella shorter than last basal joint. 



The name of this genus is from rf v, I bore, alluding to the bur- 

 rowing habits of the species of Thalassinidea. 



TRYPJSA AUSTRALIENSIS. 



From non triangulatus. Pedes antici valde compressi, brachio carpo 

 manuque pedis majoris supra acutis. Manus major lata, Icevis, carpo 

 paululo longior; digitis fere dimidii manus longitudine, non hian- 

 tibus, intiis subtiliter dentlculatls, superiore paulo longiore, arcuato, 

 carpo paulo minore quam manus, brachio cum processu cultriformi 

 juxta basin infra armato, Segmentum caudate non longius quam 

 latum, postice arcuatum, 



Front not triangular. Anterior feet much compressed, arm, carpus, 

 and hand having an acute edge above. Larger hand broad, smooth, 

 but little longer than carpus, fingers nearly half as long as hand, 

 not gaping, finely denticulate within, superior finger a little the 

 longer, arcuate, carpus somewhat smaller than hand, arm having a 

 cultriform process below near base. Caudal segment about as long 

 as broad, nearly rounded at apex. 



Plate 32, fig. 4 a, animal, natural size; 6, part of inner antennae; c, 

 part of outer maxillipeds. 



District of Illawarra, New South Wales, along shores. 



Length, two and three-fourths inches. Eyes on very short pedun- 

 cles. Outer antennae about half as long as body. Fingers with a 



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