REPORT ON THE STOMATOPODA. 9 



more typical species of the genus Squilla, such as Squilla nepa, have broad triangular eyes, 

 an elongated carinated carapace with acute spines at its antero-latcral angles, longitudinal 

 carina) on all the abdominal somites, the appendages of the exposed thoracic legs filiform, 

 and the telson longer than wide, with well-developed marginal spines, of which only the 

 submedians are on the posterior border, find the others lateral. In Squilla lata (PI. III. 

 figs. 1, 2, 3) the eyes are narrow and only slightly enlarged at their tips, the appendages of 

 the exposed thoracic limbs are flat, and the submedian carinas are absent or obsolete on 

 the first five abdominal and all the thoracic somites. In Squilla fasciata (PI. III. 

 figs. 4, 5) the eyes are cylindrical, not at all dilated at the tips, the appendao-es of the 

 exposed thoracic limbs are flat and strap-shaped, and the submedian dorsal carince are 

 completely absent on the first five abdominal somites; while in Squilla chlorida 

 (PI. II. figs. 1-5), which is not usually regarded as a Squilla, but is placed in a distinct 

 genus Chloridella, the eyes are constricted at the tips, the appendages of the exposed 

 thoracic appendages broad and flat, and the submedian carinas absent from all the 

 exposed somites except the sixth abdominal; and in Squilla [Chloridella) microphthalma 

 the eyes and appendages are like those of Squilla chlorida, but the dorsal surfaces of 

 the exposed somites are smooth, and their lateral edges but faintly carinated, and the 

 telson is wider than long, and the uropods small. In all these species the antero-lateral 

 angles of the carapace are acute, but in Squilla [Chloridella) votundicauda we have, in 

 addition to the wide telson the small uropods and eyes and antennary scales of Squilla 

 microphthalma, a loosely articulated hind body, a carapace which is rounded in front as 

 well as behind, and the posterior margin of the telson rounded. 



The series is so complete that it is quite impossible to draw any line to separate the 

 genus Squilla fi'om the genus Chloridella, and all the species must therefore be 

 associated in a single genus Squilla. It is easy to find an answer to the question, which 

 term in the series of species of Squilla is most primitive, for while the large multi- 

 carinated Squillx are so diS"erent from the Lysiosquillse that there can be no question as 

 to their distinctness, it is difficult to discover any characteristics which shall separate 

 Squilla microjjhthalma from the latter genus ; but we find that this species does not 

 resemble all species of Lysiosqicilla to an equal degree, for the genus includes species, 

 like Lysiosquilla [Coronis) excavatrix (PI. X. figs. 8-16), which have, like Squilla microph- 

 thalma, small eyes and uropods, and flat wide appendages to the exposed thoracic 

 limbs ; as well as species which, like Lysiosquilla maculata, have these appendages 

 linear and the eyes broad and triangular. We may therefore state with confidence 

 that Lysiosquilla maculata and Squilla nepa are more divergent than Lysiosquilla 

 eoccavatrix and Squilla microp>]dhahna, and that the two genera are divergent branches 

 from a common type, from which both genera have inherited the flat hind body and the 

 many-spined raptorial claw ; and that this ancestral form had small eyes, antennary 

 scales and uropods, and a transverse telson. 



(ZOOL. CHALL. EXP.— PAHT .\LV. — 1886.) Ty 2 



