^412 



PROCEEDINGS OF THE ACADEMY OF 



[Sept., 



higher than in species of the subgenus Glyptelasma, l)ut otherwise the 

 carina is very similar to that of G. subcarinatum, etc. The carina of 

 M. minus ilhistrated (fig. 4) is 4.8 mm. long; that of M. bellum (fig. 5) 

 is 7.8 mm. long. The terga are similar in general shape in M. minus, 

 M. bellum and M. carinodentatum. In the former two there is a small 

 acute tooth on the scutal margin, near the occludent end. In M. 

 striatum the terga are much higher, and are pointed at the carinal end. 



The peduncle is slightly longer in M. helium than in M. minus, 

 though it is very short in both species. 



In M. helium the first cirrus has rami of 8 segments, the outer ramus 

 broader, with the segments conspicuously convex and profusely spinose 



Fig. G. — M. minus, 7th and Stli sc{ 

 raents of ei)-nis ^'.' 



Fig. 7 



-A[. bellum, lOtli and lltli .seg- 

 ments of cirrus \'. 



on both marigns. The inner face is also profusely spinose. It is very 

 like the first cirrus of M. striatum as figured by Hoek." The inner ramus 

 is narrower, only the distal segments projecting laterally. The posterior 

 margins and inner face of each segment is spinose. The other cirri are 

 slender, with 16 to 19 segments. Except the basal and distal segments, 

 they have four pairs of large and one pair of small spines on the anterior 

 border of each segment, and a tuft of three or four unequal small spines 

 at the distal posterior angle of each segment (fig. 7, lOth and 11th 

 segments of cirrus V). 



' Challenger Report, VIII, Cirripedia, pi. 2, fig. 9. 



' In this figure the cirri of M. minus are represented on a hirger scale than those 

 of M. helium. Thej^ are actually very much smaller. 



