Mr. J. Y. Johnson on Squilla Mantis. 57 



have been drawn up from a dried, and not fully-grown, individual, 

 4i inches in length, — whereas my specimen, which is a male, 

 measures 7 inches, the narrowest part of the thorax measuring 

 1 inch across, and the widest part of the abdomen 1 h inch. 



1. The eyes are green. 2. The three tilaments of the internal 

 or supei-ior antennae are of very unequal length, the longest of 

 them measuring 2| inches, the shortest only 1 inch. 3. The 

 superior (Mr. Bell says the inferior) margin of the groove in the 

 penultimate joint of the claws which receives the six spines of the 

 terminal joint is denticulated. This groove is bridged over at 

 five places by tubercles, as if for the purpose of giving support 

 to the thin sides of the joint at their free and therefore weakened 

 edges. 4. The lateral pieces of the carapace have each two 

 longitudinal ridges or crests, all of which (Mr. Bell speaks of 

 the outei-most only) extend back to near the posterior margin. 

 This posterior margin forms an uninterrupted curve from the 

 sides inwardly. Mr. BelFs diagnosis of the specific character 

 states that the posterior margin of the middle portion of the 

 carapace is straight. 5. All the longitudinal ridges or crests of 

 the fourth, fifth, and sixth abdominal segments terminate in 

 spines ; and the lateral ridges of the first, second, and third seg- 

 ments are simdarly terminated. Mr. Bell refers to the ridges 

 of the sixth segment only as being spined. The objects that 

 look like fringed appendages upon five of the abdominal seg- 

 ments in Mr. Bell's figure are not to be found on the animal, 

 saving as depressions in the integument. In ]\Ir. Bell's specimen 

 the median ridge of the last abdominal segment (the middle 

 lobe of the tail) terminated posteriorly in an intramarginal 

 tubercle : in mine it ends in a sharp spine. At the anterior 

 extremity of this ridge there is a small tubercle on each side. 

 The colours of this segment are worthy of notice. The median 

 ridge is yellow ; the raised and thickened margin is brown ; the 

 larger portion of the superior surface of the segment is of a lively 

 purple ; and on each side of the median ridge near the front 

 margin of the segment is a large round spot of deep purple, 

 like an eye, a Cjuarter of an inch in diameter, the anterior por- 

 tion being nearly black. These spots present a remarkable 

 appearance when the animal is fresh from the water ; but they 

 disappear entirely, and the whole segment becomes in time of a 

 dull brown colour. The colour of the abdomen is a pale varied 

 purple washed with an impure white. 



I am. Gentlemen, 



Your obedient Servant, 

 James Yate Johnson. 



