1913-] S. Kemp : Crustacea Stomaiopoda of the Indo-Pacific Region. 77 



2. The anterior breadth of the carapace is less than half the median length, 



including the rostrum. 



3. The rostrum is much more strongly narrowed anteriorly and is proportionately 



a trifle longer. 



4. The anterior lateral process of the sixth thoracic somite is usually a little 



longer and narrower. 



5. The telson shows important distinctions. It has the same series of impressed 



pits as are found in other species of the group ; but, in addition, is provided 

 with rows of tubercles on either side of the middle line converging to a 

 point beneath the apex of the spine which terminates the median carina. 

 This feature is possessed by no single one of its allies. The tubercles are 

 only developed in well-grown specimens and cannot be detected in the two 

 smallest examples which measure 45 and 49 mm. The single row which can 

 be seen in a specimen 65 mm. in length is a prominent feature of all the 

 other larger examples. In very large individuals, such as those described 

 by Kossmann and Nobili and figured by Balss (1910, text-fig. 4), three rows 

 of tubercles are found, and in these the difference between S. massavensis 

 and its allies is very pronounced. In the largest specimen from the Persian 

 Gulf the row nearest the median carina is well developed, while the other 

 two are quite rudimentary. 

 There are two or three sharp tubercles on the dorsal aspect of the carpus and the 

 number of spines on the abdominal somites is the same as in 5. wood-masoni. In 

 the specimens examined there are two to four (usually three) submedian denticles, 

 seven to nine intermediate and one lateral. Nobili mentions that in the specimen 

 which he examined there are six intermediate and two (!) laterals. In the largest 

 male the carinae of the marginal telson teeth and the bases of the intermediate 

 denticles are noticeably inflated, more so than in any other species of the same group. 

 It must be confessed that had the two smallest individuals (under 50 mm. in 

 length) been found alone, and not taken in company with larger examples, the greatest 

 difficulty would have been experienced in their identification. From 5. wood-masoni 

 of similar size, they are distinguished only by the rostrum, which is more strongly 

 narrowed anteriorly, and by the different proportions of the carapace. To young 

 5. oratoria var. perpensa the resemblance is even closer ; the form of the rostrum and 

 the total absence of the anterior bifurcation of the median carina of the carapace l 

 afford almost the only means of distinction, for in immature 5. massavensis the char- 

 acteristics of the raptorial propodus and carpus are not developed and the lobe on 

 the larger spine of the basal process of the uropod is conspicuous. 



According to the authors who have previously described this species, the anterior 

 bifurcation of the median carina of the carapace is present, but this feature is not 

 shown in any of the specimens I have examined. Nobili (1906) considers that the 

 two small tubercles found on the last five abdominal somites between the interme- 



1 The presence of the anterior part of this bifurcation is not absolutely constant in S. oratoria var. 

 perpensa. 



