GLYPHOCRANGON ALATA. 137 



Family GLYPHOCRANGONID^. 

 GLYPHOCRANGON A. M. Edw. 



Ann. Sci. Nat., Zoul., 6™" Ser., Vol. XL, No. 4, p. 3, ISSl. 



Glyphocrangon alata Fax. 

 Plate XXXVII. 



Bull. Mus. Comp. Zool., XXIV. 201, 189.3. 



The rostrum is armed with a pair of lateral spines on a level with the 

 anterior end of the eye ; posterior to this pair of spines follows a variable 

 number of smaller marginal spines (three to five on each side). The anterior 

 half of the rostrum is unarmed, although the margins are ciliated. A light 

 spinulose carina runs along the median line of the rostrum from the base to 

 the anterior third (in some specimens this carina is obsolete). On each side 

 of the median line there are, on the basal portion of the rostrum, four or 

 five small spinules. 



The carapace and abdomen are thickly tuberculated. On the antero- 

 lateral regions of the carapace and on the abdominal pleurae the tubercles 

 assume a spiny character. For the rest, the tubercles are for the most 

 part laterally compressed, their tops truncated and more or less eroded. It 

 is further to be observed of these tubercles that they are arranged in longi- 

 tudinal rows, and six of these rows on each side of the carapace by their 

 greater prominence form imperfect carinae corresponding in position to those 

 commonly found in species of this genus. The external orbital spine is 

 directed upward at an angle of 45°, is curved (with the concavity inward), 

 but hardly deflected outward. The spine at the antero-lateral angle of the 

 carapace is turned somewhat downward and outward. Between these two 

 spines and just behind them is a strong spinous tooth, acute at the end, and 

 vertically compressed, its base broadening out in such a fa.shion that the whole 

 tooth forms an acute-tipped wing-like expansion. This is, in fact, the greatly 

 developed anterior portion of the fourth carina (counting from the median 

 line). Behind it the carina continues on, as a low toothed ridge, to the 

 cervical groove. The broad triangular area between this carinal tooth and 

 the gastric region is thickly beset with laterally compressed spinous tuber- 

 cles like those which adorn the other parts of the carapace. 



A.n interrupted median dorsal carina runs along the abdomen. Upon the 



