378 PR. W. M. TATTERSALL ON THE STOMATOPODA AND 



S. quadridens, S. qitadrispi.no sus, 8. trispinosvs, and 8. septemspinosus, the 

 specific names of which refer to the number of teeth on the posterior margin 

 of the sixth abdominal somite. Following this nomenclature, the specific 

 name of the new species here described indicates at once the main point of 

 difference from the species described by De Man. Among De Man's species, 

 S. quinquedens is at once distinguished from 8. triacanthus, 8. trispinosus, 

 and 8. septemspinosus by the character of the rostral plate. In the first two 

 species the central spine is exceedingly long, much longer than the lateral 

 teeth and as long as or longer than the first joint of the antennular peduncle. 

 In S. septemspinosus the central prong of the rostral trident is longer than 

 the laterals, whereas in S. quinquedens all three are equal. S. trispinosus 

 and S. septemspinosus are further distinguished from 8. quinquedens by 

 having the merus of the third legs armed with seven or eight spinules. Of 

 the other three species, S. quinquedens approaches most closely to 8. quadri- 

 spinosus, differing only in the extra spine on the sixth abdominal segment. 



This group of species is most nearly related to the type-form of the 

 division of the genus to which they belong, *S V . biunguiculatus, and in fact, 

 but for the armature of the sixth abdominal somite, would be difficult to 

 separate from that species. 



Genus Alpheus, Fabricius. 

 Macrochirus group. 



Alpheus gracilis, Heller, 1861, p. 271, Taf. 3. figs. 19, 20. 

 See De Man, 191] 6, p. 337, pi. 14. fig. 60. 



Localities. Station VII. B, 1 £, 16 mm., 1 ? with eggs, 17 mm. 

 Station IX. A, 4 J, 9-17 mm., 4 ? , 9-16 mm., three of which, 12-16 mm. 

 in length, were carrying eggs. 



Distribution. The type-form has so far not been met with outside the Bed 

 Sea, from which both Heller and Coutiere have recorded the species. The 

 var. alluaudi, Coutiere, is known from Mahe and the var. luciparensis, 

 De Man, from Lucipara Island in the Dutch East Indies. 



Alpheus ventrosus *, H. M.-Ed., 1837, p. 352. 



A. ventrosus, Coutiere, 1905, p. 882. 

 A. ventrosus. De Man, 1911 b, p. 339. 



Localities. Station VII. B, six specimens. Station V. E, several. 



Distribution. Becorded previously from the Bed Sea by Heller, Paulson, 

 Kossmann, De Man, Miers, Nobili, and Coutiere ; widely distributed through- 

 out the Indian and Pacific Oceans. 



* Stebbing (1915) identifies this species with the earlier described Alpheus lottini, Gufirin, 

 which name it should accordingly bear. 



