STOMATOPODA— CALMAN. 141 



representing a "Variety C" of liis Squilla panamensis. Of this specimen he writes: 

 " In the shape of its body, the arrangement of pigmented areas in the integument, and 

 the form of its eyes, it resembles S. panamensis very much, and the edge of the telson 

 appears to have begun to thicken, so it is probably better to regard it as belonging to 

 this species rather than to S. emjjusa." In the " Terra Nova" specimens the marginal 

 thickening is, at most, no greater than in specimens of S. empusa of similar size, but 

 it is less distinctly broken up into separate swellings at the bases of the denticles, and so 

 far it resembles the condition found in S. panamensis. The pigmentation of the body 

 appears to agree with that described by Bigelow, more especially as regards the two 

 dark spots on the telson. The characters given as distinguishing the variety C from 

 the typical form of the species (from the Bay of Panama) are not of great importance, 

 but they are all, with the exception possibly of the elongated rostrum, present in our 

 specimens. The lateral processes of the fifth thoracic somite are not described in the 

 variety, but in the typical form they are described and figured as only slightly curved, 

 differing conspicuously from the strongly hooked processes in all the " Terra Nova " 

 specimens. Bigelow does not mention the form of the anterior margin of the carapace, 

 which appears to be the most conspicuous distinction between our specimens and 

 S. empusa. Under these circumstances it appears best to record the Brazilian specimens 

 under a new specific name, leaving it for future work to decide their precise relationshij) 

 to the allied forms of the Pacific coast.. 



Among the characters that have been little used in classifying the species of this 

 genus, the number of thoracic epipodites and the relative positions of the " dorsal pit " 

 and the anterior bifurcation of the median carina of the carapace appear to deserve 

 attention. The following key utilising these characters deals only with those Atlantic 

 species nearly related to 8. mantis that are represented by spirit-specimens in the 

 Museum collection. 



A. Epipodites present on first five pairs of thoracic appendages. 



a. Anterior margin of carapace on each side of rostrum concave and nearly transverse. 



a. Anterior bifurcation of median carina of carapace extending two-thirds of distance from 



frontal margin to dorsal pit ....... <S. mantis, Latr. 



b. Anterior bifurcation extending at least five-sixths of this distance . S. empusa, Say. 



b. Anterior margin on each side of rostrum straight and sloping backwards S. brasiliensis, n. sp. 



B. Epipodites on first four pairs of thoracic appendages. Anterior margin on each side of rostrum 



concave and slightly oblique. Anterior bifurcation of median carina interrupted, extending 

 two-thirds of distance from frontal margin to dorsal pit . . . S. africana, Caiman. 



C. Epipodites on first three pairs of thoracic appendages. Anterior margin on each side of rostrum 



nearly straight and sloping backwards. Anterior bifurcation of median carina obscure, extending 

 for less than half the distance from frontal margin to dorsal pit . . S. diibia, M.-Edw. 



2. Squilla, sp. (near S. quadridens, Bigelow). 



Occurrence. — Station 40. Six miles off mouth of Rio de Janeiro Harbour. 

 Plankton at 2 metres depth. One male. 



Remarks. — The specimen, which measures 1 1 mm. in total length, is in an early 

 post-larval stage. The dactylus of the raptorial limb has four teeth, including the 



