214) Capt. A. C. MacGilchrist on Decapod Crustacea 



mm. 



Length of carapace, excluding rostrum and poste- 

 rior spines 105 



Length of rostrum with its spine 22 



„ spines at base of rostrum 18 



„ hirger spines of carapace 14-28 



,, smaller ., ,, 3-5 



„ larger spines on margin of carapace .... 12-28 

 ,, smaller „ „ „ .... 3-8 



Greatest breadth of dorsal surface of carapace, ex- 

 cluding spines 93 



Tlie large spines on tlic carapace are less numerous than 

 in any of the specimens described by Smith; in all other 

 details this specimen agrees with Smith's description. 



The gastric region is armed with three pairs of large spines, 

 the cardiac region with two pairs, the intestinal with one 

 pair, and the branchial region on either side with six large 

 spines j the more posterior of these twelve pairs of sjjines on 

 the dorsum of the carapace are longer than the anterior, and 

 dotted in between these dorsal spines are about an equal 

 number of smaller spines about 4 the size of the large spines. 

 On the margin of the carapace behind the large hepatic spine 

 and the cervical suture are 9 large spijies and '2-7 intervening 

 smaller spines about half (or less) the size of the hirger. 

 These marginal spines are not exactly symmetrical in place 

 or size on the two sides. There is a small median spine in 

 the sinus in the middle of the posterior border of the 

 carapace. 



This specimen differs very little from Smith's larger adult 

 specimen. Like the latter it is nine tenths as broad as long, 

 and. the number of large spines differ only on the branchial 

 regions and margin of carapace, where the difference in 

 length of the larger and smaller spines may not have been 

 so pronounced as in this specimen. The rostral spine, how- 

 ever, and the spines at its base are much longer in this 

 specimen, being as long as the average large spine on the 

 carapace, and resemble those of Smith's smaller adult 

 specimen. 



The abdomen has three large outstanding spines situated 

 on the central plate which represents the fused first and 

 second abdominal terga ; the other spines on the abdomen 

 are small in comparison with these three. 



A figure will be given in the next issue of '^ Illustrations 

 of the Zoology of R.I. M.S. ' Investigator.' " 



