528 



HEPOBT OX TEE OBDEB STOMATOPODA—BIGELOW. 



TELSON OK SQUILLA PANAMENSIS. 

 M;»lc Slightly enlarged. 



rouiided and iiiucronate or subacute iu tlie typical form. All the cari- 

 nas ou the fourth, fifth and sixth abdominal somites end iu spines, and 

 there is a spine in front of the articulation of each uropod. In the 

 first abdominal somite only the marginal carime end iu spines; the 

 second has si)ines terminating the lateral carinas as well as the mar- 

 ginal ones, and the third has also spines 

 on the intermediate ones. There is a 

 very slight median tubercle on all but 

 the first and sixth abdominal segments. 

 In full-grown males the marginal carinse 

 are thickened. Tliis tbickening extends 

 as a broad elevation along t!ie posterior 

 margin and involves the greater part of 

 the lateral carimie. There is no trace of 

 any such thickening in the females. 



In the female of the typical form the 

 crest of the telsou ends in a snuill spine . 

 aud behind it there is a small tubercle. 

 The six marginal spines are slender and 

 acute and have basal carinre. There is 

 also a distinct anterior lateral pair of 

 carina^. The denticles are large and 

 rounded and have smaller elevations at their bases. The dorsal surface 

 is marked on each side by a row of shallow pits, running nearly parallel 

 to the crest and a series of about a dozen curved lijies of pits, running 

 outward and backward. The ventral surface has an exactly similar 

 arrangement of these sculpturings. There is also a keel extending 

 about half way from the anus to the median sinus, and there is a iiair 

 of lateral carin.ie. In full-grown males the crest and the dorsal side 

 of the' margin of the telsou are very much thickened (fig. 18). The 

 basal elevations of the denticles on the medial side of each carina 

 form with it a continuous ridge, while there is a distinct furrow sepa- 

 rating the carina from the elevations on its lateral side. The marginal 

 thickening is greatest at the bases of the spines. 



Theeyes are broadly triangular. The corneal axis is oblique andabout 

 one-fifth longer than the peduncular axis, while it is about five one- 

 hundredths of the total length of the body. The spines atthebasesof 

 the eyes are erect and truncated. The first three joints of the first 

 antenuse are about equal in length to the carapace. The second antennse 

 are about as long as this and the antennary scale is very nearly 

 two-thirds as long. The raptorial claw is strongly developed. The 

 carpus has a series of teeth on its anterior margin. The outer margin 

 of the dactylus is not sinua>te and has no tubercle or one that is hardly 

 perceptible near the articulation. The appendages on the walking- 

 legs are slightly si^atulate or sinuate. The basal prolongation of the 

 nropod is finely serrated ou the inner side aud the inner spine is twice 

 as long as the outer one, aud has a minute lobe on th<'. outer sicle in the 



