CRUSTACEA OF ALABAMA. 47 



the second attaining the end of the frontal spine and bearing a short inner and longer 

 outer flagellum, each being simple. In Palcemonetes vulgaris, the common prawn, the 

 outer flagellum is palpate, and Pandahts leptoceros, the deep water shrimp, has no such 

 evident scaphocerite. The tergite of the occular segment is distinct, the basal segment 

 of the pedulcle being trapezoidal, the eyes very large and obliquely attached, not termi- 

 nal as in Palaemonetes. Antennary lamella rather broadly ovate, forming an acute point, 

 abruptly truncate within at the base and emarginated, basal segment of endocerite short, 

 following' one longer, together about one fourth as long as the lamella, terminating in an 

 enormously elongate flagellum. Hypostome protuberant, triangular. Mandible with 

 large rhombic lamellate palp and minute teeth upon the comminuting edge. The first 

 maxilliped is of good size, the ischiopodite being very short and anchylosed with the 

 basipodite, which bears the long, flat, multiarticulate and bristly exopodite, the meropo- 

 dite is long and unsculptured, the three following segments being small and hairy. The 

 lower maxilliped has an exopodite like that of the first maxilliped, but shorter. The 

 ischiopodite of the limb is longer than the meropodite, the joints diminishing toward- the 

 end, which is not chelate. The first leg is shorter and has a minute exopodite and the 

 ischiopodite over half the length of the second or meropodite segment and is chelate, 

 the third leg is longest and similar to the second, the fourth and fifth are similar and not 

 chelate. The five anterior abdominal segments are furnished with similar, biramose 

 swimmerets, of which the inner ramus is always less. 



The last (sixth) abdominal segment is very high and carinate above, its swimmerets 

 being very powerful, the exopodite being exactly in size and shape like the lamella of 

 the antenna, extending half its length beyond the telson, which is narrow, very acute, 

 and deeply grooved above. 



Penaeus brasilensis, Latniik. 



This species was found in Mobile bay during July. This species may be at once 

 distinguished from the preceeding by the fact that the frontal spine is continued back- 

 wards as a low crest to the posterior margin of the carapace. Total length of specimens 

 70 mm. Antennae 120 mm., thorax and spine 25 mm., telson 10 mm., exopodite of tail- 

 fin 12 mm. The antennules are shorter than in P. setiferus, the flagellar, especially, be- 

 ing shorter ; the peduncle of the antennae very short, flagellum less than once-and-one- 

 half the length of the entire body, antennary lamella as long as the spine. Chelae of 

 first three limbs nearly smooth, proportions of the limbs much as in previous species. 



FAMILY ASTACID.E. 



(Craw-Fish.) 



Genus Cambarus. 



1. Cambarus advena, Hagen. 



2. Cambarus alabamensis, Faxton. 



