1894. 



PROCEEDINGS OF TEE NATIONAL MUSEUM, 



517 



posterior lateral edge wliere it is suddenly produced into a sharp si^ine 

 directed backwaril and outward. 



The segments of the abdomen, except the sixth, and the telson are 

 all provided with siibmediau, intermediate, lateral, and marginal carinse; 

 the latter are absent in the sixth segment. All the carinas end pos- 

 teriorly in sharp spines except the snbmediau ones in the first five 

 segments. In the ])osterior margin of the fifth segment on each side, 

 half way between the submedian and intermediate earinjie, there are 

 from one to four spines grouped together. 



Tlietelsoii (fig. 0) has little or no indicatioii of an anterior lateral 

 carina or spine. The submedian spines are jointed so that they have 

 each a short and acute movable tip. The ventral surface has a keel 

 which is deepest just posterior to the anus. The rest of the surface .is 

 smooth except for an obsolete series of curved lines corresx)ondiug 

 with those of the dorsal surface. Between the submeditin spines the 

 margin is divided by a deep median sinus into two rounded lobes very 

 much as in A'. Jata^ and there are no teeth ])resent except sometimes 

 very minute dentations on the posterior edge. Between a submedian 

 and intermediate spine there are ten or eleven conical teeth and 

 between each intermediate and lateral spine there is one. These are 

 Aery small elevations at the base of each tooth and spine. 



The eyes are triangular, the corneal portion equals in length the 

 distance along the inner edge of the eye from the.anterior end of the 

 corneal part to the anterior edge 

 of the hard part of the stalk. 

 The median jirocess of the ocu- 

 lar segment is subacute. The 

 lateral processes are rounded 

 laterally, but the anterior mar- 

 gin of each gives rise to a stout, 

 straiglit, rounded spine which 

 points forward and slightly out- 

 ward opposite the inner edge of 

 the eye. The first antenna' are 

 nearly as long as the carapace 

 and exposed tlioracic segments 

 taken together. The antennary 

 segment bears a pair of stout 

 lateral processes curved forward and sharply acute. 



The flagellum of the second antenna does not reach quite to the base 

 of the riagellum of the first antenna. 



The raptorial claw (fig. 10) is stout. The dactylus is armed with 

 seven to nine teeth, rarely six. There are three movable spines and a 

 row of pectinations on the manus as usual. The anterior edge of the 

 carinis has one tooth- like projection. 



Fig. 10. 



RAPTORIAL CLAW OF SQUILLA ARMATA. 



Ne.irly three times natural .size. 



