NATURAL SCIENCES OP PHILADELPHIA. 203 



Width across nasal meatus If in. 



Length of gonys 2 " 



Teeth | 



Delphinus crotaphiscus sp. nov. 



This species belongs to the same group as the styx, euphrosyne, (?) 

 and asthenops, resembling most especially the last. Its prominent fea- 

 tures are the flat muzzle, with carina in front of the blow-holes, the very small 

 temporal fossa, and the shallow trace on each side of the roof of the mouth, 

 of the groove so prominent in the delphis group. 



The paroccipital aire are moderately developed. The glenoid cavity sends 

 no gutter on the inner border of the squamosal process, but its inner margin 

 is produced into a lamina, which is weaker than in the Delphinapterus. Pala- 

 tines terminating next the orbitosphenoids in a free keel, and with a strong 

 lateral keel. Occiput broad, rounded, short. Basioceipital groove and sella 

 turcica shallow ; corpus olivare represented by a transverse ridge. Triangle 

 extending beyond the line of posterior teeth. 



Tn. Line?. 



Length from end of muzzle to occipital condyle 16 



" " " to notch 10 



" of gonys 2 



Breadth at notch , 3 9 



" at middle of muzzle 2 1*5 



" at postorbital process '. 7 7 



" between temporal crests 5 c 



Teeth 4 2 



4 3 



Habitat. Unknown. -Mus. Salem, Mass. E. W. Putnam. 



Delphinus microps, Gray, 1. c, p. 126. Zool. E. T., pi. 25. 



Two crania, resembling closely Gray's figure quoted, differ from the pre- 

 ceding as given in the table, and in the shorter basal premaxillary triangle. 

 The premaxillary ridge is strong, rounded, and the surface not at all con- 

 tinuous with that of the maxillaries. Proportions as follows : 



537 S94 



Length from notch to occipital condyle 6 in. ,5-75 in. 



" " " middle of supraoccipital crest... 4.3 in. 4-5 " 



" " " end of muzzle lOf " 10*75" 



Width of muzzle at notch 3 " 3 " 



" " middle 1-75 " If " 



" between outlines of frontal expansion 6 " 6 " 



" of temporal crests 5 " 4-5 " 



" across blow-holes 1| " 1-5 " 



Length of gonys 2| " 2 " 



Delphinus an sp. nov. ? vel delphis, varietas. 



A single skull, from the Morton collection, stated to have been brought from 

 the Indian Ocean ; is very near those of the delphis, but has smaller nasal 

 meatus and heavier proportions than our specimens of the latter. It resembles 

 rather the cranium of the D. fulvivittatus, Lesson, figured in Voy. d. 

 1' Astrolabe et Zel6, in the nearly equal width of the muzzle ; but the temporal 

 fossa is elongate in the direction of the axis of the skull, as in most species, 

 and not vertical to it. The D. brevimanus, Lesson, 1. c, differs in the 

 much more prominent occiput and the smaller number of teeth. The cranium 

 ofD. novaezelandiae is not described. In D. s a o the palatal grooves are 

 much shorter. General proportions as follows : 



Length from notch to occipital crest 5 in. 3 1. 



" " " end of muzzle 10" 9 1. 



" ofgonys : 1" 101. 



1865] 



